Signaling for energy harvesting at a device

ABSTRACT

Methods, systems, and devices for wireless communications are described that support signaling for energy harvesting at a first device. In some examples, the first device may transmit, to a second device, an indication of one or more an energy conversion efficiency factors, power threshold parameters, power levels, battery power levels, or the like. Based on receiving the indication of the one or more of the characteristics, the second device may determine a radio frequency power for subsequent signaling. The second device may transmit a signal having the determined radio frequency power, and the first device may receive the signaling and convert at least a first portion of the radio frequency power to direct current (DC) power.

INTRODUCTION

The following relates to wireless communications, and more specificallyto managing signals at a device.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such asLong Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, orLTE-A Pro systems, and fifth generation (5G) systems which may bereferred to as New Radio (NR) systems. These systems may employtechnologies such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonalfrequency division multiplexing (DFT-S-OFDM). A wireless multiple-accesscommunications system may include one or more base stations or one ormore network access nodes, each simultaneously supporting communicationfor multiple communication devices, which may be otherwise known as userequipment (UE).

SUMMARY

A method for wireless communication at a first device is described. Themethod may include transmitting, to a second device, an indication of anenergy conversion efficiency factor and a threshold power parameter, Themethod may further include receiving, from the second device, a signalincluding a radio frequency power, where the radio frequency power isbased on the transmitted indication, and converting at least a firstportion of the radio frequency power of the signal to direct current(DC) power.

An apparatus for wireless communication at a first device is described.The apparatus may include a processor, memory coupled to the processor,the processor and memory configured to transmit, to a second device, anindication of an energy conversion efficiency factor and a thresholdpower parameter, The processor and memory may be configured further toreceive, from the second device, a signal including a radio frequencypower, where the radio frequency power is based on the transmittedindication, and convert at least a first portion of the radio frequencypower of the signal to DC power.

Another apparatus for wireless communication at a first device isdescribed. The apparatus may include means for transmitting, to a seconddevice, an indication of an energy conversion efficiency factor and athreshold power parameter, The apparatus may further include means forreceiving, from the second device, a signal including a radio frequencypower, where the radio frequency power is based on the transmittedindication, and means for converting at least a first portion of theradio frequency power of the signal to DC power.

A non-transitory computer-readable medium storing code for wirelesscommunication at a first device is described. The code may includeinstructions executable by a processor to transmit, to a second device,an indication of an energy conversion efficiency factor and a thresholdpower parameter, The code may further include instructions executable bythe processor to receive, from the second device, a signal including aradio frequency power, where the radio frequency power is based on thetransmitted indication, and convert at least a first portion of theradio frequency power of the signal to DC power.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to thesecond device, a second indication of one or more additional energyconversion efficiency factors.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining, by thefirst device, a model associated with an efficiency of energyharvesting, where the energy conversion efficiency factor and the one ormore additional energy conversion efficiency factors may be based on themodel.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to thesecond device, a second indication of a target amount of converted DCpower, where the radio frequency power of the received signal may befurther based on the target amount of converted DC power.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting the secondindication via a media access control (MAC) control element (CE), atransmission via a physical uplink channel, or a combination thereof.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting theindication via radio resource control (RRC) signaling, a MAC-CE, controlinformation, or a combination thereof.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for storing the DC power atthe first device based on the converting.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for decoding the signalbased on a second portion of the radio frequency power of the signal.

A method for wireless communication at a first device is described. Themethod may include transmitting, to a second device, an indication of aset of power levels including a first quantity of input radio frequencypower levels and a second quantity of output DC power levels. The methodmay further include receiving, from the second device, a signal having aradio frequency power that is based on the transmitted indication, andconverting at least a first portion of the radio frequency power of thesignal to DC power.

An apparatus for wireless communication at a first device is described.The apparatus may include a processor, memory coupled to the processor,the processor and memory configured to transmit, to a second device, anindication of a set of power levels including a first quantity of inputradio frequency power levels and a second quantity of output DC powerlevels, The processor and memory may further be configured to receive,from the second device, a signal having a radio frequency power that isbased on the transmitted indication, and convert at least a firstportion of the radio frequency power of the signal to DC power.

Another apparatus for wireless communication at a first device isdescribed. The apparatus may include means for transmitting, to a seconddevice, an indication of a set of power levels including a firstquantity of input radio frequency power levels and a second quantity ofoutput DC power levels. The apparatus may further include means forreceiving, from the second device, a signal having a radio frequencypower that is based on the transmitted indication, and means forconverting at least a first portion of the radio frequency power of thesignal to DC power.

A non-transitory computer-readable medium storing code for wirelesscommunication at a first device is described. The code may includeinstructions executable by a processor to transmit, to a second device,an indication of a set of power levels including a first quantity ofinput radio frequency power levels and a second quantity of output DCpower levels. The code may further include instructions executable bythe processor to receive, from the second device, a signal having aradio frequency power that is based on the transmitted indication, andconvert at least a first portion of the radio frequency power of thesignal to DC power.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting a mappingbetween the first quantity of input radio frequency power levels and thesecond quantity of output DC power levels.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining, for eachof the first quantity of input radio frequency power levels, acorresponding one of the second quantity of output DC power levels,where transmitting the indication may be based on the determining.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to thesecond device, a second indication of a target amount of converted DCpower, where the radio frequency power of the received signal may bebased on the target amount of converted DC power.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting the secondindication via a MAC-CE, a transmission via a physical uplink channel,or a combination thereof.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting theindication via RRC signaling, a MAC-CE, control information, or acombination thereof.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for storing the DC power atthe first device based on the converting.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for decoding the signalbased on a second portion of the radio frequency power of the signal.

A method for wireless communication at a first device is described. Themethod may include transmitting, to a second device, a first indicationof a first power level of a battery of the first device, receiving, fromthe second device, a signal including a radio frequency power, where theradio frequency power is based on the transmitted first indication. Themethod may further include storing at least a first portion of the radiofrequency power of the signal as DC power at the first device, andtransmitting, based on the storing, a second indication of a secondpower level of the battery to the second device.

An apparatus for wireless communication at a first device is described.The apparatus may include a processor, memory coupled to the processor,the processor and memory configured to transmit, to a second device, afirst indication of a first power level of a battery of the firstdevice, receive, from the second device, a signal including a radiofrequency power, where the radio frequency power is based on thetransmitted first indication. The processor and memory may further beconfigured to store at least a first portion of the radio frequencypower of the signal as DC power at the first device, and transmit, basedon the storing, a second indication of a second power level of thebattery to the second device.

Another apparatus for wireless communication at a first device isdescribed. The apparatus may include means for transmitting, to a seconddevice, a first indication of a first power level of a battery of thefirst device, means for receiving, from the second device, a signalincluding a radio frequency power, where the radio frequency power isbased on the transmitted first indication. The apparatus may furtherinclude means for storing at least a first portion of the radiofrequency power of the signal as DC power at the first device, and meansfor transmitting, based on the storing, a second indication of a secondpower level of the battery to the second device.

A non-transitory computer-readable medium storing code for wirelesscommunication at a first device is described. The code may includeinstructions executable by a processor to transmit, to a second device,a first indication of a first power level of a battery of the firstdevice, receive, from the second device, a signal including a radiofrequency power, where the radio frequency power is based on thetransmitted first indication. The code may further include instructionsexecutable by the processor to store at least a first portion of theradio frequency power of the signal as DC power at the first device, andtransmit, based on the storing, a second indication of a second powerlevel of the battery to the second device.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from thesecond device, a request for the second indication of the second powerlevel of the battery, where transmitting the second indication may bebased on receiving the request for the second indication from the seconddevice.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to thesecond device, a third indication of a type of the battery of the firstdevice, where receiving the signal may be based on transmitting thethird indication of the type of the battery of the first device.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to thesecond device, a third indication of a target amount of converted DCpower, where the radio frequency power of the received signal may bebased on the target amount of converted DC power.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting the secondindication via a MAC-CE, a transmission via a physical uplink channel,or a combination thereof.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from thesecond device, a second signal including a second radio frequency powerthat may be based on the second power level of the battery, wherereceiving the second signal may be based on transmitting the secondindication.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for converting at least thefirst portion of the radio frequency power of the signal to the DCpower, where the storing may be based on the converting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system thatsupports signaling for energy harvesting at a device in accordance withone or more aspects of the present disclosure.

FIG. 2 illustrates an example of a system that supports signaling forenergy harvesting at a device in accordance with one or more aspects ofthe present disclosure.

FIGS. 3 through 5 illustrate examples of process flows that supportsignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure.

FIGS. 6A through 6C illustrates examples of energy harvesting schemesthat support signaling for energy harvesting at a device in accordancewith one or more aspects of the present disclosure.

FIG. 7 illustrates an example of circuitry that supports signaling forenergy harvesting at a device in accordance with one or more aspects ofthe present disclosure.

FIG. 8 illustrates an example of a power diagram that supports signalingfor energy harvesting at a device in accordance with one or more aspectsof the present disclosure.

FIGS. 9 and 10 show block diagrams of devices that support signaling forenergy harvesting at a device in accordance with one or more aspects ofthe present disclosure.

FIG. 11 shows a block diagram of a communications manager that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure.

FIGS. 12 through 16 show flowcharts illustrating methods that supportsignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure.

DETAILED DESCRIPTION

In some cases, wireless communication systems may support techniques forradio frequency energy harvesting. For example, a wirelesscommunications system may include various devices, such as a UE, a basestation, a wearable device, or other devices. In some cases, a firstdevice (e.g., a UE, a base station, any sidelink enabled device) may beconfigured to perform energy harvesting by converting received radiofrequency power associated with wireless signals received from a seconddevice (e.g., a UE, a base station, any sidelink enabled device) to DCpower. In some examples, the first device may be configured to convertreceived radio frequency power to DC power and store the converted DCpower at the first device. For example, the second device may transmitsignals with a determined radio frequency power to the first device. Thefirst device may include a signal decoding circuit to receive and decodesignals from the second device as well as an energy harvesting circuitto convert radio frequency power to DC power. In some examples, theenergy harvesting circuit may perform (e.g., take inputs and produceoutputs) according to one or more characteristics (e.g., a thresholdpower parameter, an energy conversion efficiency factor, power levels,or the like).

In some examples, the first device may transmit signaling indicating oneor more parameters associated with the energy harvesting to the seconddevice. Based on receiving the signaling indicating the one or moreparameters, the second device may adjust a radio frequency power ofsignals transmitted to the first wireless device. For example, thesecond device may adjust the radio frequency power of signalstransmitted to the first wireless device to increase an efficiency ofthe energy harvesting performed by the first device.

In some wireless communications systems, the first device may transmit,to a second device, an indication of energy conversion efficiencyfactors, power threshold parameters, power levels, or a combinationthereof. For example, the first device may transmit an indication of theenergy conversion efficiency factor, a threshold power parameter, orboth, to the second device. The energy conversion efficiency factor mayrepresent an efficiency of the energy harvesting circuit to convertradio frequency power to DC power. For example, an energy conversionefficiency factor of 50% may represent that the first device may convert50% of radio frequency power input to the energy harvesting circuit toDC power output from the energy harvesting circuit. Additionally, thethreshold power parameter may represent a maximum radio frequency powerthat the energy harvesting circuit may convert to DC power. For example,the energy harvesting circuit may convert a portion of radio frequencypower input into the energy harvesting circuit to DC power (e.g., wherethe portion corresponds to the energy conversion efficiency power) untilthe input radio frequency power reaches the threshold power parameter.That is, the energy harvesting circuit may output a same quantity of DCpower in response to the maximum radio frequency power being input andmore than the maximum radio frequency power being input to the energyharvesting circuit. Based on receiving the indication from the firstdevice, the second device may determine a radio frequency power forsubsequent signaling to the first device, according to the indication.For example, the second device may adjust the radio frequency power ofsubsequent signals to increase a power efficiency associated with theenergy harvesting circuit at the first device and maintain a certainquality of service (QoS). That is, the second device may avoidtransmitting signals having more radio frequency power than the firstdevice has the capability to convert to DC power (e.g., based on thethreshold power parameter associated with the energy harvestingcircuit). Additionally, the second device may attempt to transmitsignals having sufficient radio frequency power to ensure that a radiofrequency power of signals received by the signal decoding circuit ofthe first device are associated with a desired QoS.

Utilizing the techniques as described herein may enable the seconddevice to transmit signals having a radio frequency power that is basedon parameters associated with the energy harvesting at the first device.In some cases, the second device transmitting signals based on thedetermined radio frequency power (e.g., that is based on the parametersassociated with the energy harvesting at the second device) may resultin power savings at the first device and the second device and anextended battery life at the first device. Additionally, configuring thesecond device to transmit signals based on the determined radiofrequency power may result in more reliable communications between thefirst device and the second devices (e.g., when compared tocommunications where the second device does not transmit signals to thefirst device having a radio frequency power that is based on theparameters associated with the energy harvesting at the first device)That is, the second device may adjust the radio frequency power based onthe parameters to increase a probability of achieving a desired QoS.

Aspects of the disclosure are initially described in the context ofsystems and process flows. Aspects of the disclosure are then describedin the context of energy harvesting schemes and circuitry. Aspects ofthe disclosure are further illustrated by and described with referenceto apparatus diagrams, system diagrams, and flowcharts that relate tosignaling for energy harvesting at a device.

FIG. 1 illustrates an example of a wireless communications system 100that supports signaling for energy harvesting at a device in accordancewith one or more aspects of the present disclosure. The wirelesscommunications system 100 may include one or more base stations 105, oneor more UEs 115, and a core network 130. In some examples, the wirelesscommunications system 100 may be an LTE network, an LTE-A network, anLTE-A Pro network, or an NR network. In some examples, the wirelesscommunications system 100 may support enhanced broadband communications,ultra-reliable (e.g., mission critical) communications, low latencycommunications, communications with low-cost and low-complexity devices,or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area toform the wireless communications system 100 and may be devices indifferent forms or having different capabilities. The base stations 105and the UEs 115 may wirelessly communicate via one or more communicationlinks 125. Each base station 105 may provide a coverage area 110 overwhich the UEs 115 and the base station 105 may establish one or morecommunication links 125. The coverage area 110 may be an example of ageographic area over which a base station 105 and a UE 115 may supportthe communication of signals according to one or more radio accesstechnologies.

The UEs 115 may be dispersed throughout a coverage area 110 of thewireless communications system 100, and each UE 115 may be stationary,or mobile, or both at different times. The UEs 115 may be devices indifferent forms or having different capabilities. Some example UEs 115are illustrated in FIG. 1 . The UEs 115 described herein may be able tocommunicate with various types of devices, such as other UEs 115, thebase stations 105, or network equipment (e.g., core network nodes, relaydevices, integrated access and backhaul (IAB) nodes, or other networkequipment), as shown in FIG. 1 .

The base stations 105 may communicate with the core network 130, or withone another, or both. For example, the base stations 105 may interfacewith the core network 130 through one or more backhaul links 120 (e.g.,via an S1, N2, N3, or other interface). The base stations 105 maycommunicate with one another over the backhaul links 120 (e.g., via anX2, Xn, or other interface) either directly (e.g., directly between basestations 105), or indirectly (e.g., via core network 130), or both. Insome examples, the backhaul links 120 may be or include one or morewireless links. A UE 115 may communicate with the core network 130through a communication link 155.

One or more of the base stations 105 described herein may include or maybe referred to by a person having ordinary skill in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or agiga-NodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or other suitable terminology.

A UE 115 may include or may be referred to as a mobile device, awireless device, a remote device, a handheld device, or a subscriberdevice, or some other suitable terminology, where the “device” may alsobe referred to as a unit, a station, a terminal, or a client, amongother examples. A UE 115 may also include or may be referred to as apersonal electronic device such as a cellular phone, a personal digitalassistant (PDA), a tablet computer, a laptop computer, or a personalcomputer. In some examples, a UE 115 may include or be referred to as awireless local loop (WLL) station, an Internet of Things (IoT) device,an Internet of Everything (IoE) device, or a machine type communications(MTC) device, among other examples, which may be implemented in variousobjects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with varioustypes of devices, such as other UEs 115 that may sometimes act as relaysas well as the base stations 105 and the network equipment includingmacro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations,among other examples, as shown in FIG. 1 .

The UEs 115 and the base stations 105 may wirelessly communicate withone another via one or more communication links 125 over one or morecarriers. The term “carrier” may refer to a set of radio frequencyspectrum resources having a defined physical layer structure forsupporting the communication links 125. For example, a carrier used fora communication link 125 may include a portion of a radio frequencyspectrum band (e.g., a bandwidth part (BWP)) that is operated accordingto one or more physical layer channels for a given radio accesstechnology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layerchannel may carry acquisition signaling (e.g., synchronization signals,system information), control signaling that coordinates operation forthe carrier, user data, or other signaling. The wireless communicationssystem 100 may support communication with a UE 115 using carrieraggregation or multi-carrier operation. A UE 115 may be configured withmultiple downlink component carriers and one or more uplink componentcarriers according to a carrier aggregation configuration. Carrieraggregation may be used with both frequency division duplexing (FDD) andtime division duplexing (TDD) component carriers.

In some examples (e.g., in a carrier aggregation configuration), acarrier may also have acquisition signaling or control signaling thatcoordinates operations for other carriers. A carrier may be associatedwith a frequency channel (e.g., an evolved universal mobiletelecommunication system terrestrial radio access (E-UTRA) absoluteradio frequency channel number (EARFCN)) and may be positioned accordingto a channel raster for discovery by the UEs 115. A carrier may beoperated in a standalone mode where initial acquisition and connectionmay be conducted by the UEs 115 via the carrier, or the carrier may beoperated in a non-standalone mode where a connection is anchored using adifferent carrier (e.g., of the same or a different radio accesstechnology).

The communication links 125 shown in the wireless communications system100 may include uplink transmissions from a UE 115 to a base station105, or downlink transmissions from a base station 105 to a UE 115.Carriers may carry downlink or uplink communications (e.g., in an FDDmode) or may be configured to carry downlink and uplink communications(e.g., in a TDD mode).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of determined bandwidths for carriers of a particular radioaccess technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz(MHz)). Devices of the wireless communications system 100 (e.g., thebase stations 105, the UEs 115, or both) may have hardwareconfigurations that support communications over a particular carrierbandwidth or may be configurable to support communications over one of aset of carrier bandwidths. In some examples, the wireless communicationssystem 100 may include base stations 105 or UEs 115 that supportsimultaneous communications via carriers associated with multiplecarrier bandwidths. In some examples, each served UE 115 may beconfigured for operating over portions (e.g., a sub-band, a BWP) or allof a carrier bandwidth.

Signal waveforms transmitted over a carrier may be made up of multiplesubcarriers (e.g., using multi-carrier modulation (MCM) techniques suchas orthogonal frequency division multiplexing (OFDM) or DFT-S-OFDM). Ina system employing MCM techniques, a resource element may consist of onesymbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme, thecoding rate of the modulation scheme, or both). Thus, the more resourceelements that a UE 115 receives and the higher the order of themodulation scheme, the higher the data rate may be for the UE 115. Awireless communications resource may refer to a combination of a radiofrequency spectrum resource, a time resource, and a spatial resource(e.g., spatial layers or beams), and the use of multiple spatial layersmay further increase the data rate or data integrity for communicationswith a UE 115.

The time intervals for the base stations 105 or the UEs 115 may beexpressed in multiples of a basic time unit which may, for example,refer to a sampling period of T_(s)=1/(Δf_(max)·N_(f)) seconds, whereΔf_(max) may represent the maximum supported subcarrier spacing, andN_(f) may represent the maximum supported discrete Fourier transform(DFT) size. Time intervals of a communications resource may be organizedaccording to radio frames each having a specified duration (e.g., 10milliseconds (ms)). Each radio frame may be identified by a system framenumber (SFN) (e.g., ranging from 0 to 1023).

Each frame may include multiple consecutively numbered subframes orslots, and each subframe or slot may have the same duration. In someexamples, a frame may be divided (e.g., in the time domain) intosubframes, and each subframe may be further divided into a number ofslots. Alternatively, each frame may include a variable number of slots,and the number of slots may depend on subcarrier spacing. Each slot mayinclude a number of symbol periods (e.g., depending on the length of thecyclic prefix prepended to each symbol period). In some wirelesscommunications systems 100, a slot may further be divided into multiplemini-slots containing one or more symbols. Excluding the cyclic prefix,each symbol period may contain one or more (e.g., N_(f)) samplingperiods. The duration of a symbol period may depend on the subcarrierspacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallestscheduling unit (e.g., in the time domain) of the wirelesscommunications system 100 and may be referred to as a transmission timeinterval (TTI). In some examples, the TTI duration (e.g., the number ofsymbol periods in a TTI) may be variable. Additionally or alternatively,the smallest scheduling unit of the wireless communications system 100may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using one or more oftime division multiplexing (TDM) techniques, frequency divisionmultiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A controlregion (e.g., a control resource set (CORESET)) for a physical controlchannel may be defined by a number of symbol periods and may extendacross the system bandwidth or a subset of the system bandwidth of thecarrier. One or more control regions (e.g., CORESETs) may be configuredfor a set of the UEs 115. For example, one or more of the UEs 115 maymonitor or search control regions for control information according toone or more search space sets, and each search space set may include oneor multiple control channel candidates in one or more aggregation levelsarranged in a cascaded manner. An aggregation level for a controlchannel candidate may refer to a number of control channel resources(e.g., control channel elements (CCEs)) associated with encodedinformation for a control information format having a given payloadsize. Search space sets may include common search space sets configuredfor sending control information to multiple UEs 115 and UE-specificsearch space sets for sending control information to a specific UE 115.

Each base station 105 may provide communication coverage via one or morecells, for example a macro cell, a small cell, a hot spot, or othertypes of cells, or any combination thereof. The term “cell” may refer toa logical communication entity used for communication with a basestation 105 (e.g., over a carrier) and may be associated with anidentifier for distinguishing neighboring cells (e.g., a physical cellidentifier (PCID), a virtual cell identifier (VCID), or others). In someexamples, a cell may also refer to a geographic coverage area 110 or aportion of a geographic coverage area 110 (e.g., a sector) over whichthe logical communication entity operates. Such cells may range fromsmaller areas (e.g., a structure, a subset of structure) to larger areasdepending on various factors such as the capabilities of the basestation 105. For example, a cell may be or include a building, a subsetof a building, or exterior spaces between or overlapping with geographiccoverage areas 110, among other examples.

A macro cell may covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by theUEs 115 with service subscriptions with the network provider supportingthe macro cell. A small cell may be associated with a lower-powered basestation 105, as compared with a macro cell, and a small cell may operatein the same or different (e.g., licensed, unlicensed) frequency bands asmacro cells. Small cells may provide unrestricted access to the UEs 115with service subscriptions with the network provider or may providerestricted access to the UEs 115 having an association with the smallcell (e.g., the UEs 115 in a closed subscriber group (CSG), the UEs 115associated with users in a home or office). A base station 105 maysupport one or multiple cells and may also support communications overthe one or more cells using one or multiple component carriers.

In some examples, a carrier may support multiple cells, and differentcells may be configured according to different protocol types (e.g.,MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that mayprovide access for different types of devices.

In some examples, a base station 105 may be movable and thereforeprovide communication coverage for a moving geographic coverage area110. In some examples, different geographic coverage areas 110associated with different technologies may overlap, but the differentgeographic coverage areas 110 may be supported by the same base station105. In other examples, the overlapping geographic coverage areas 110associated with different technologies may be supported by differentbase stations 105. The wireless communications system 100 may include,for example, a heterogeneous network in which different types of thebase stations 105 provide coverage for various geographic coverage areas110 using the same or different radio access technologies.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, as opposedto transmission and reception simultaneously). In some examples,half-duplex communications may be performed at a reduced peak rate.Other power conservation techniques for the UEs 115 include entering apower saving deep sleep mode when unengaged in active communications,operating over a limited bandwidth (e.g., according to narrowbandcommunications), or a combination of these techniques. For example, someUEs 115 may be configured for operation using a narrowband protocol typethat is associated with a defined portion or range (e.g., set ofsubcarriers or resource blocks (RBs)) within a carrier, within aguard-band of a carrier, or outside of a carrier.

The wireless communications system 100 may be configured to supportultra-reliable communications or low-latency communications, or variouscombinations thereof. For example, the wireless communications system100 may be configured to support ultra-reliable low-latencycommunications (URLLC) or mission critical communications. The UEs 115may be designed to support ultra-reliable, low-latency, or criticalfunctions (e.g., mission critical functions). Ultra-reliablecommunications may include private communication or group communicationand may be supported by one or more mission critical services such asmission critical push-to-talk (MCPTT), mission critical video (MCVideo),or mission critical data (MCData). Support for mission criticalfunctions may include prioritization of services, and mission criticalservices may be used for public safety or general commercialapplications. The terms ultra-reliable, low-latency, mission critical,and ultra-reliable low-latency may be used interchangeably herein.

In some examples, a UE 115 may also be able to communicate directly withother UEs 115 over a device-to-device (D2D) communication link 135(e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115utilizing D2D communications may be within the geographic coverage area110 of a base station 105. Other UEs 115 in such a group may be outsidethe geographic coverage area 110 of a base station 105 or be otherwiseunable to receive transmissions from a base station 105. In someexamples, groups of the UEs 115 communicating via D2D communications mayutilize a one-to-many (1:M) system in which each UE 115 transmits toevery other UE 115 in the group. In some examples, a base station 105facilitates the scheduling of resources for D2D communications. In othercases, D2D communications are carried out between the UEs 115 withoutthe involvement of a base station 105.

In some systems, the D2D communication link 135 may be an example of acommunication channel, such as a sidelink communication channel, betweenvehicles (e.g., UEs 115). In some cases, a communication link 135 may bereferred to as a sidelink communication link and may be used forsidelink communications between UEs 115. In some cases, a sidelinkcommunication link as described herein may additionally or alternativelyrepresent an example of a relay link 165, where the relay link 165 maybe used to relay information (e.g., data, control information) from afirst UE 115 to a second UE 115. In some cases, the relay link 165 mayadditionally or alternatively be an example of a communication link 135.In some examples, vehicles may communicate using vehicle-to-everything(V2X) communications, vehicle-to-vehicle (V2V) communications, or somecombination of these. A vehicle may signal information related totraffic conditions, signal scheduling, weather, safety, emergencies, orany other information relevant to a V2X system. In some examples,vehicles in a V2X system may communicate with roadside infrastructure,such as roadside units, or with the network via one or more networknodes (e.g., base stations 105) using vehicle-to-network (V2N)communications, or with both.

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC) or 5G core (5GC), which may include at leastone control plane entity that manages access and mobility (e.g., amobility management entity (MME), an access and mobility managementfunction (AMF)) and at least one user plane entity that routes packetsor interconnects to external networks (e.g., a serving gateway (S-GW), aPacket Data Network (PDN) gateway (P-GW), or a user plane function(UPF)). The control plane entity may manage non-access stratum (NAS)functions such as mobility, authentication, and bearer management forthe UEs 115 served by the base stations 105 associated with the corenetwork 130. User IP packets may be transferred through the user planeentity, which may provide IP address allocation as well as otherfunctions. The user plane entity may be connected to IP services 150 forone or more network operators. The IP services 150 may include access tothe Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or aPacket-Switched Streaming Service.

Some of the network devices, such as a base station 105, may includesubcomponents such as an access network entity 140, which may be anexample of an access node controller (ANC). Each access network entity140 may communicate with the UEs 115 through one or more other accessnetwork transmission entities 145, which may be referred to as radioheads, smart radio heads, or transmission/reception points (TRPs). Eachaccess network transmission entity 145 may include one or more antennapanels. In some configurations, various functions of each access networkentity 140 or base station 105 may be distributed across various networkdevices (e.g., radio heads and ANCs) or consolidated into a singlenetwork device (e.g., a base station 105).

The wireless communications system 100 may operate using one or morefrequency bands, in some cases, in the range of 300 megahertz (MHz) to300 gigahertz (GHz). In some cases, the region from 300 MHz to 3 GHz isknown as the ultra-high frequency (UHF) region or decimeter band becausethe wavelengths range from approximately one decimeter to one meter inlength. The UHF waves may be blocked or redirected by buildings andenvironmental features, but the waves may penetrate structuressufficiently for a macro cell to provide service to the UEs 115 locatedindoors. The transmission of UHF waves may be associated with smallerantennas and shorter ranges (e.g., less than 100 kilometers) compared totransmission using the smaller frequencies and longer waves of the highfrequency (HF) or very high frequency (VHF) portion of the spectrumbelow 300 MHz.

The wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band, or in an extremely high frequency (EHF)region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as themillimeter band. In some examples, the wireless communications system100 may support millimeter wave (mmW) communications between the UEs 115and the base stations 105, and EHF antennas of the respective devicesmay be smaller and more closely spaced than UHF antennas. In someexamples, this may facilitate use of antenna arrays within a device. Thepropagation of EHF transmissions, however, may be subject to evengreater atmospheric attenuation and shorter range than SHF or UHFtransmissions. The techniques disclosed herein may be employed acrosstransmissions that use one or more different frequency regions, anddesignated use of bands across these frequency regions may differ bycountry or regulating body.

The wireless communications system 100 may utilize both licensed andunlicensed radio frequency spectrum bands. For example, the wirelesscommunications system 100 may employ License Assisted Access (LAA),LTE-Unlicensed (LTE-U) radio access technology, or NR technology in anunlicensed band such as the 5 GHz industrial, scientific, and medical(ISM) band. When operating in unlicensed radio frequency spectrum bands,devices such as the base stations 105 and the UEs 115 may employ carriersensing for collision detection and avoidance. In some examples,operations in unlicensed bands may be based on a carrier aggregationconfiguration in conjunction with component carriers operating in alicensed band (e.g., LAA). Operations in unlicensed spectrum may includedownlink transmissions, uplink transmissions, P2P transmissions, or D2Dtransmissions, among other examples.

The electromagnetic spectrum is often subdivided, based onfrequency/wavelength, into various classes, bands, channels, etc. In 5GNR two initial operating bands have been identified as frequency rangedesignations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Itshould be understood that although a portion of FR1 is greater than 6GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band invarious documents and articles. A similar nomenclature issue sometimesoccurs with regard to FR2, which is often referred to (interchangeably)as a “millimeter wave” band in documents and articles, despite beingdifferent from the extremely high frequency (EHF) band (30 GHz-300 GHz)which is identified by the International Telecommunications Union (ITU)as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-bandfrequencies. Recent 5G NR studies have identified an operating band forthese mid-band frequencies as frequency range designation FR3 (7.125GHz-24.25 GHz). Frequency bands falling within FR3 may inherit FR1characteristics and/or FR2 characteristics, and thus may effectivelyextend features of FR1 and/or FR2 into mid-band frequencies. Inaddition, higher frequency bands are currently being explored to extend5G NR operation beyond 52.6 GHz. For example, three higher operatingbands have been identified as frequency range designations FR4a or FR4-1(52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300GHz). Each of these higher frequency bands falls within the EHF band.

With the above aspects in mind, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like if usedherein may broadly represent frequencies that may be less than 6 GHz,may be within FR1, or may include mid-band frequencies. Further, unlessspecifically stated otherwise, it should be understood that the term“millimeter wave” or the like if used herein may broadly representfrequencies that may include mid-band frequencies, may be within FR2,FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band.

A base station 105 or a UE 115 may be equipped with multiple antennas,which may be used to employ techniques such as transmit diversity,receive diversity, multiple-input multiple-output (MIMO) communications,or beamforming. The antennas of a base station 105 or a UE 115 may belocated within one or more antenna arrays or antenna panels, which maysupport MIMO operations or transmit or receive beamforming. For example,one or more base station antennas or antenna arrays may be co-located atan antenna assembly, such as an antenna tower. In some examples,antennas or antenna arrays associated with a base station 105 may belocated in diverse geographic locations. A base station 105 may have anantenna array with a number of rows and columns of antenna ports thatthe base station 105 may use to support beamforming of communicationswith a UE 115. Likewise, a UE 115 may have one or more antenna arraysthat may support various MIMO or beamforming operations. Additionally oralternatively, an antenna panel may support radio frequency beamformingfor a signal transmitted via an antenna port.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105, a UE 115) to shape or steeran antenna beam (e.g., a transmit beam, a receive beam) along a spatialpath between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that some signals propagatingat particular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying amplitude offsets, phase offsets, or both to signals carriedvia the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

A base station 105 or a UE 115 may use beam sweeping techniques as partof beam forming operations. For example, a base station 105 may usemultiple antennas or antenna arrays (e.g., antenna panels) to conductbeamforming operations for directional communications with a UE 115.Some signals (e.g., synchronization signals, reference signals, beamselection signals, or other control signals) may be transmitted by abase station 105 multiple times in different directions. For example,the base station 105 may transmit a signal according to differentbeamforming weight sets associated with different directions oftransmission. Transmissions in different beam directions may be used toidentify (e.g., by a transmitting device, such as a base station 105, orby a receiving device, such as a UE 115) a beam direction for latertransmission or reception by the base station 105.

Some signals, such as data signals associated with a particularreceiving device, may be transmitted by a base station 105 in a singlebeam direction (e.g., a direction associated with the receiving device,such as a UE 115). In some examples, the beam direction associated withtransmissions along a single beam direction may be determined based on asignal that was transmitted in one or more beam directions. For example,a UE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions and may report to the base station105 an indication of the signal that the UE 115 received with a highestsignal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a base station 105or a UE 115) may be performed using multiple beam directions, and thedevice may use a combination of digital precoding or radio frequencybeamforming to generate a combined beam for transmission (e.g., from abase station 105 to a UE 115). The UE 115 may report feedback thatindicates precoding weights for one or more beam directions, and thefeedback may correspond to a configured number of beams across a systembandwidth or one or more sub-bands. The base station 105 may transmit areference signal (e.g., a cell-specific reference signal (CRS), achannel state information reference signal (CSI-RS)), which may beprecoded or unprecoded. The UE 115 may provide feedback for beamselection, which may be a precoding matrix indicator (PMI) orcodebook-based feedback (e.g., a multi-panel type codebook, a linearcombination type codebook, a port selection type codebook). Althoughthese techniques are described with reference to signals transmitted inone or more directions by a base station 105, a UE 115 may employsimilar techniques for transmitting signals multiple times in differentdirections (e.g., for identifying a beam direction for subsequenttransmission or reception by the UE 115) or for transmitting a signal ina single direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE 115) may try multiple receiveconfigurations (e.g., directional listening) when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets (e.g., differentdirectional listening weight sets) applied to signals received atmultiple antenna elements of an antenna array, or by processing receivedsignals according to different receive beamforming weight sets appliedto signals received at multiple antenna elements of an antenna array,any of which may be referred to as “listening” according to differentreceive configurations or receive directions. In some examples, areceiving device may use a single receive configuration to receive alonga single beam direction (e.g., when receiving a data signal). The singlereceive configuration may be aligned in a beam direction determinedbased on listening according to different receive configurationdirections (e.g., a beam direction determined to have a highest signalstrength, highest signal-to-noise ratio (SNR), or otherwise acceptablesignal quality based on listening according to multiple beamdirections).

The wireless communications system 100 may support various techniquesfor energy harvesting. Energy harvesting may include acquiring energyfrom an energy source (e.g., a radio frequency wave, a conducting wire)and using or storing the acquired energy for any task that maycorrespond to, or otherwise be associated with, energy harvesting. Insome examples, wireless communications system 100 may include a device103 that is configured to perform energy harvesting. That is, the device103 may include an energy harvesting circuit 104 that has the capabilityof converting received radio frequency power to DC power. In some cases,the device 103 may then store the DC power (e.g., converted by theenergy harvesting circuit 104 from radio frequency power) at an energystorage 107 (e.g., a battery) of the device 103. In some cases, thedevice 103 may be configured to both harvest radio frequency energy(e.g., using the energy harvesting circuit 104) and decode radiofrequency transmissions (e.g., using a signal decoding circuit 106).Additionally, radio frequency sources (e.g., radio frequencytransmissions) may provide controllable and relatively constant energytransfer over distances, where the energy harvested may be predictableand relatively stable over time.

In some examples, the device 103 may transmit an indication, to a radiofrequency source (e.g., a UE 115, a base station 105, any sidelinkenabled device), of one or more characteristics (e.g., a threshold powerparameter, an energy conversion efficiency factor, power levels, or thelike) of the energy harvesting circuit 106. Based on receiving theindication of the one or more of the characteristics of the energyharvesting circuit 106 from the device 103, the radio frequency sourcemay determine a radio frequency power for subsequent signaling accordingto the indicated characteristics. In some examples, the radio frequencysource may avoid transmitting signals having more radio frequency powerthan the device 103 has the capability of converting to DC power (e.g.,based on a threshold power parameter associated with the energyharvesting circuit 104). Additionally, the radio frequency source mayattempt to transmit signals having sufficient radio frequency power toensure that a radio frequency power of signals received by the signaldecoding circuit 106 of the device 103 are associated with a desiredQoS. Thus, the radio frequency source may transmit signals based on thedetermined radio frequency power which may result in power savings,extended battery life, and reliable communications.

In some examples, the device 103 may be an example of a base station 105where one or more of the operations of the device 103 may be performedby a base station communications manager 102, which may be an example ofa communications manager 820, 920, 1020, or 1120 as described withreference to FIGS. 8 through 11 . In some cases, a transceiver mayperform receiving or transmitting operations and a processor maydetermine one or more radio frequency powers.

In some examples, the device 103 may be an example of a UE 115 where oneor more of the operations of the device 103 may be performed by a UEcommunications manager 101, which may be an example of a communicationsmanager 820, 920, 1020, or 1120 as described with reference to FIGS. 8through 11 . In some cases, a transceiver may perform the receiving ortransmitting operations and a processor may perform administrative taskssuch as preparing indications, decoding data, storing converted radiofrequency power, or any other task at the UE 115.

FIG. 2 illustrates an example of a system 200 that supports signalingfor energy harvesting at a device 205 in accordance with one or moreaspects of the present disclosure. In some examples, system 200 mayimplement aspects of system 100. For example, system 200 may includedevice 205-a and device 205-b, which may be examples of a device 103, aUE 115, a base station 105, a sidelink enabled device, or any otherdevice as described with reference to FIG. 1 .

In some cases, system 200 may support methods for radio frequency energyharvesting. That is, system 200 may include devices 205 configured toconvert received radio frequency power 240 to DC power 245 and store theconverted DC power 245 (e.g., at a battery 225, such as energy storage107 as described with reference to FIG. 1 , of the device 205). In someinstances, a device 205 may rely on radio frequency energy harvesting toprovide a controllable and constant energy transfer over a distance toone or more other devices 205. For example, device 205-b may transmitsignals 235 with a determined radio frequency power 240 to device 205-a.Here, device 205-a may include a signal decoding circuit 215, such assignal decoding circuit 106 as described with reference to FIG. 1 , toreceive and decode the signal 235 from device 205-b. Additionally,device 205-a may include an energy harvesting circuit 220, such asenergy harvesting circuit 104 as described with reference to FIG. 1 , toconvert at least a portion of the radio frequency power 240 of thesignal 235 to DC power 245. For example, the energy harvesting circuit220 may convert energy from an electromagnetic domain to an electricaldomain. For example, the energy harvesting circuit 220 may receive theradio frequency power 240 (e.g., having power associated with anelectromagnetic field) and may convert the radio frequency power 240 toDC power 245 (e.g., having power associated with a voltage and current).As such, device 205-a may convert at least a portion of the receivedradio frequency power 240 to DC power 245 and store the converted DCpower 245 at device 205-a (e.g., within the battery 225). In some cases,device 205-a may use the stored energy to perform low energy tasksincluding tasks associated with information transfer such as decoding orencoding data, analog-to-digital signal conversion, processing referencesignals, transmitting reference signals, operations while in an idle orotherwise inactive state, or other tasks that are associated withrelatively low energy consumption (e.g., when compared to other tasksperformed by device 205-a that consume more energy).

The energy harvested by device 205-a may depend on a number of factors.In some cases, a device 205 may predict an amount of energy obtainedwhen harvesting energy according to an energy harvesting model (e.g.,that considers one or more of the number of factors). As an illustrativeexample, device 205-a may predict the amount of energy obtained whenharvesting energy using the energy harvesting model illustrated byEquation 1:

E _(j) =ηP _(i) |g _(i-j)|² T  (1)

In Equation 1, η may be an energy conversion efficiency factor (e.g., aradio frequency-to-DC conversion efficiency) and may be a characteristicof the energy harvesting circuit 220. Further, P_(i) may be a radiofrequency power 240 of a signal 235 transmitted from a transmitting node(e.g., device 205-b). Additionally, g_(i-j) may be a channel attenuationfactor (e.g., representing path fading) that may depend on channelconditions such as channel quality, interference, or the like betweenthe transmitting node and a receiving node (e.g., device 305-a).Additionally, T may be a time allocated for energy harvesting at device205-a. Combined, these factors may result in E_(j), an amount of energyharvested at device 205-a.

Equation 1 may be an example of a linear energy harvesting model. Forinstance, the amount of energy harvested at device 205-a may increaselinearly with an increase in the radio frequency power 240. The slope ofEquation 1 may correspond to the energy conversion efficiency factor(e.g., given a constant channel attenuation factor and time allocatedfor energy harvesting).

In some cases, a device 205 may predict an amount of energy obtainedwhen harvesting energy according to a non-linear energy harvesting model(e.g., that considers one or more of the number of factors). Forexample, device 205-a may predict the amount of energy obtained whenharvesting energy using the energy harvesting model that is based on athreshold power P_(th) associated with the energy harvesting circuit220. The threshold power P_(th) may correspond to a radio frequencypower level where a characteristic of the energy harvesting circuit 220changes. For example, up until the radio frequency power levelcorresponding to the threshold power P_(th), the amount of energy outputby the energy harvesting circuit 220 may increase linearly as the inputradio frequency power 240 increases. Additionally, beyond the radiofrequency power level corresponding to the threshold power P_(th), anincrease in the radio frequency power 240 input into the energyharvesting circuit 220 may result in little (or no) change to the DCpower 245 output from the energy harvesting circuit 220.

In one example, device 205-a may predict the amount of energy obtainedwhen harvesting energy using the energy harvesting model illustrated byEquation 2, where the energy E_(j) harvested by device 205-a is based onthe threshold power P_(th) of the energy harvesting circuit 220. Thatis, device 205-a may utilize a piecewise energy harvesting model basedon whether the radio frequency power 240 being input to the energyharvesting circuit 220 is less than the threshold power P_(th) of theenergy harvesting circuit 220 or greater than the threshold power P_(th)of the energy harvesting circuit 220.

$\begin{matrix}\left\{ \begin{matrix}{{E_{j} = {\eta P_{i}{❘g_{i - j}❘}^{2}T}},} & {{{P_{i}{❘g_{i - j}❘}^{2}} < P_{th}},} \\{{E_{j} = {\eta P_{th}T}},} & {{P_{i}{❘g_{i - j}❘}^{2}} \geq {P_{th}.}}\end{matrix} \right. & (2)\end{matrix}$

In Equation 2, when radio frequency power 240 being input to the energyharvesting circuit 220 is less than the threshold power P_(th) of theenergy harvesting circuit 220, device 205-a may predict the amount ofenergy obtained using a linear model, for example, according to themodel represented by Equation 1. When radio frequency power 240 beinginput to the energy harvesting circuit 220 is greater than the thresholdpower P_(th) of the energy harvesting circuit 220, device 205-a maypredict the amount of energy obtained as substantially unchanging. Thatis, for increasing radio frequency power 240 being input to the energyharvesting circuit greater than the threshold power P_(th), the amountof energy obtained may stay the same. In the case of Equation 2, theamount of energy obtained may be equal to the combination of η: theenergy conversion efficiency factor (e.g., a radio frequency-to-DCconversion efficiency), T: the time allocated for energy harvesting atdevice 205-a, and the threshold power P_(th).

In some other cases, device 205-a may predict the amount of energyobtained when harvesting energy according to a different non-linearenergy harvesting model. For example, device 205-a may predict theamount of energy obtained when harvesting energy using the energyharvesting model illustrated by Equation 3, where the energy E_(j)harvested by device 205-a is based on a polynomial energy harvestingmodel. The polynomial energy harvesting model may be an example of aK-coefficient polynomial model (e.g., where K corresponds to a quantityof coefficients in the polynomial model), where the relationship betweeninput power to the energy harvesting circuit and the amount of energyharvested by device 205-a may be represented by a finite power series.As an illustrative example, the polynomial may represent therelationship between input power to the energy harvesting circuit andthe amount of energy harvested by device 305-a with Equation 3:

$\begin{matrix}\left\{ \begin{matrix}{{P_{out} = {{{\eta_{1}(L)}P_{in}} + {{\eta_{2}(L)}P_{in}^{2}} + \ldots + {{\eta_{K}(L)}P_{in}^{K}}}},} & {P_{in} \leq {P_{th}(L)}} \\{{P_{out} = {{\eta_{th}(L)}{P_{th}(L)}}},} & {P_{in} > {P_{th}(L)}}\end{matrix} \right. & (3)\end{matrix}$

In Equation 3, η_(K) may be the Kth coefficient of the polynomial andmay be inherent to the circuit. In other words, η_(K) may depend on oneor more circuit characteristics (e.g., diodes, inductors, or othercomponents) and may be associated with energy conversion efficiency.P_(in) may be the power input to the energy harvesting circuit and maybe less than P_(th) may be, a threshold power associated with the energyharvesting circuit. P_(out) may be the energy harvested by device 305-aand may equal the minimum of the K-coefficient polynomial and thecombination of the threshold power and the energy conversion efficiencythreshold η_(th).

In some examples, the polynomial energy harvesting model may have aquantity of regions each associated with a unique behavior of the energyharvesting circuitry (e.g., the parameters in the polynomial may varyfrom region to region). In the example of Equation 3, η_(K)(L) may bedependent on a region (L) of the energy harvesting model. That is theenergy conversion efficiency factors for a first range of P_(in) maydiffer from the energy conversion efficiency factors for a second rangeof P_(in). For example, the power output from the energy harvestingcircuit may be represented by a polynomial energy harvesting modelincluding three regions (e.g., L=3). As such, η_(K) (1) may be differentfrom η_(K)(2), η_(K) (2) may be different from η_(K)(3), and so on, forany value of K. Likewise, P_(th)(L) may be dependent on a region (L) ofthe energy harvesting model. That is, each range of power input to theenergy harvesting circuit may correspond to a different threshold power.Each threshold power may be associated with a regional energy conversionefficiency factor η_(th)(L), where η_(th)(L) may represent the energyconversion efficiency for a particular region (L).

By way of example, in a first region, the power input to the energyharvesting circuit may be less than the combination of the thresholdpower and the regional energy conversion efficiency factor for the firstregion (e.g., P_(th)(1), η_(th)(1)). As such, the power output from theenergy harvesting circuit may be represented by the polynomial for thefirst region (e.g., η_(K)(1)). If the power input to the energyharvesting circuit is more than the combination of the threshold powerand the regional efficiency factor for the first region, the poweroutput from the energy harvesting circuit maybe represented by thecombination of the threshold power and the regional efficiency factorfor the first region. In some examples, the power input to the energyharvesting circuit may surpass a regional threshold. That is, the powerinput to the energy harvesting circuit may increase from a value in apower range associated with the first region to a value in a power rangeassociated with a second region. As such, the power output from theenergy harvesting circuit may be represented by the polynomial modelwith parameters shifted accordingly (e.g., η_(K)(2), P_(th)(2),η_(th)(2)).

Additionally or alternatively, the regions of the polynomial energyharvesting model may be represented with one or more defining points ofthe model (e.g., the curve). In some examples, the polynomial energyharvesting model may be defined based on a regional curve start point(e.g., P_(Start)(L)) a saturation portion start point (e.g.,P_(th LOW)(L)), and a saturation portion end point (e.g., P_(th HIGH)(L)). For example, the energy harvesting model may be a piecewise linearenergy harvesting model. In such a case, the energy harvesting model mayhave a single region (e.g., L=1). P_(Start)(1) may be (or may besubstantially near) zero, P_(th LOW)(1) may be located at P_(th)(1).That is, P_(th LOW)(1) may be located at the regional saturation point.P_(th HIGH)(1)) may be located at the end of the region, which in thecase of a piecewise linear energy harvesting model, may be infinity. Insome examples, this definition scheme may be used for a polynomialenergy harvesting model. Starting from the first region (e.g., L=1), forexample, P_(Start)(1) may be (or may be substantially near) zero,P_(th LOW)(1) may be located at P_(th)(1), and P_(th HIGH)(1)) may belocated at the end of the region, which in the case of a polynomiallinear energy harvesting model, may be located at P_(Start)(2). That is,the end point for a region may be (or may be substantially equal to) thestart point for the next region. In some cases, the end point for aregion in the polynomial energy harvesting model may be equal toinfinity. For example, the polynomial energy harvesting model may havethree regions. That is, there may be no region (e.g., according to thedescription herein) following the third region. As such, P_(th HIGH) (3)may be equal to infinity.

In some cases, device 205-b may be unaware of one or morecharacteristics of the energy harvesting circuit 220. That is, device205-b may be unaware of a threshold power parameter, an energyconversion factor, or other characteristics of the energy harvestingcircuit 220. In cases where device 205-b is unaware of one or more ofthe characteristics of the energy harvesting circuit 220 of anotherdevice 205, the device 205-b may additionally be unaware of potentialinefficiencies when transmitting signals 235 to the other device 205.For example, device 205-b may transmit, to device 205-a, a signal 235having a radio frequency power 240 such that the radio frequency power240 input into the energy harvesting circuit 220 exceeds the thresholdpower of the energy harvesting circuit 220. Here, device 205-b may usemore transmission resources than necessary which may result ininefficient communications, excessive power loss, and the like. Inanother example, device 205-b may transmit, to device 205-a, a signal235 having a radio frequency power 240 such that the radio frequencypower 240 input to the signal decoding circuit 215 results in adecreased QoS. That is, the radio frequency power 240 of the signal 235input to the signal decoding circuit 215 may be too low to enable thesignal decoding circuit 215 to successfully decode the signal 235.

In the example of wireless communications system 200, a device 205-athat performs energy harvesting may transmit, to device 205-b, anindication 230 of one or more characteristics of an energy harvestingcircuit 220. That is, the device 205-a may transmit the indication 230of one or more characteristics of the energy harvesting circuit 220based on an energy harvesting model associated with the energyharvesting circuit 220. In some cases, the indication 230 may include anindication of parameters associated with the energy harvesting circuit220 (e.g., corresponding to an energy harvesting model). Additionally oralternatively, the indication 230 may include an indication of aperformance of the energy harvesting circuit 220 (e.g., based on variousinput radio frequency power levels). In either case, transmitting theindication 230 to the device 205-b may enable the device 205-b totransmit the signal 235 having a power level that enables the device205-a to both perform energy harvesting via the energy harvestingcircuit 220 and decode the signal 235 via the signal decoding circuit215.

In cases that the indication 230 indicates one or more parametersassociated with the energy harvesting circuit 220, the indication 230may include an energy conversion efficiency factor and a threshold powerparameter associated with the energy harvesting circuit 220. For alinear energy harvesting model (e.g., as described with reference toEquation 1), the indication 230 may include the energy conversionefficiency factor of the energy harvesting circuit 220. For a piecewiselinear energy harvesting model (e.g., as described with reference toEquation 2), the indication 230 may include the energy conversionefficiency factor and the threshold power parameter representing thethreshold power of the energy harvesting circuit 220. For the polynomialenergy harvesting model (e.g., as described with reference to Equation3), the indication 230 may include multiple energy conversion efficiencyfactors associated with the energy harvesting circuit 220 (e.g.,corresponding to the coefficients of each term of the polynomial).Additionally, the indication 230 may include a quantity of the terms inthe polynomial and the threshold power parameter.

In cases that the indication 230 indicates a performance of the energyharvesting circuit 220, the indication 230 may include one or more powerlevels output from the energy harvesting circuit 220 that correspond toone or more power levels being input to the energy harvesting circuit220. For example, the indication 230 may include a power table,representing the relationship between the input power to the energyharvesting circuit 220 and the energy harvested by device 205-a. In someexamples, device 205-b may transmit an indication requesting the powertable from device 205-a. The indication may include an increment thatdevice 205-a may use to generate the power table. Likewise, device 205-amay transmit the power table including input powers (and correspondingtransmit powers) from a minimum input power to a maximum input powerwith intermediate input powers spaced at the increment. Additionally,the indication 230 may include a target amount of converted power asdescribed herein.

Additionally, the indication 230 may include information about energyharvesting procedures, supporting circuitry enabling energy harvesting,or a combination thereof. That is, the indication 230 may include targetpower levels (e.g., that enable device 205-b to transmit signals 235with sufficient power), battery power levels, and the like. For example,the indication 230 may include a target amount of converted power. Thatis, device 205-a may signal a target energy harvesting power within theindication 230 and may be associated with a desired QoS. The targetenergy harvesting power may be represented by a table for potentiallevels, predefined at device 205-a and 205-b and determined bysubsequent signaling, quantization levels determined based on signalingbetween the devices 205, or the like. In another example, the indication230 may include a power level. The power level may be associated with abattery of device 205-a. The power level may represent an energy statusof device 205-a, for example, relative to the size (or capacity) of thebattery and may be presented as a percentage, a level, a decimal, or thelike. Upon connection establishment, a wake up procedure, or the like,device 205-a may transmit the indication 230 including a first powerlevel (e.g., an initial amount of energy) as well as the type of battery(e.g., a lithium ion battery, a lithium polymer battery, or any type ofbattery) of device 205-a. In some examples, device 205-a may transmitthe indication including the power level in response to an event such asa request from device 205-b, a specific battery level (e.g., a lowbattery level), or any other event.

Device 205-b may receive the indication 230 and determine a radiofrequency power 240 for one or more subsequent radio signals 235 (e.g.,based on the information included in the indication 230). For example,device 205-b may adjust the radio frequency power 240 of the radiosignals 235 to increase a power efficiency associated with the energyharvesting circuit 220 at device 205-a and maintain a certain QoS. Thatis, device 205-b may avoid transmitting radio signals 235 having moreradio frequency power 240 than device 205-a has the capability ofconverting to DC power (e.g., based on the threshold power parameterassociated with the energy harvesting circuit 220). Additionally, device205-b may attempt to transmit radio signals 235 having sufficient radiofrequency power 240 to ensure that a radio frequency power 240 of radiosignals 235 received by the signal decoding circuit of device 205-a areassociated with the desired QoS. Thus, the second device may transmitsignals based on the determined radio frequency power 240 which mayresult in power savings, extended battery life, and reliablecommunications.

FIG. 3 illustrates an example of a process flow 300 that supportssignaling for energy harvesting at a device 305 in accordance with oneor more aspects of the present disclosure. In some examples, processflow 300 may implement aspects of the systems 100 and 200 as describedwith reference to FIGS. 1 and 2 . For example, the process flow 300 mayillustrate an example of a device 305-a transmitting an indication todevice 305-b. The indication may include characteristics associated withenergy harvesting circuitry at the device 305-a. Device 305-a and device305-b may be examples of device 205-a and device 205-b, respectively, asdescribed with reference to FIG. 2 . Alternative examples of thefollowing may be implemented, where some processes are performed in adifferent order than described or are not performed. In some cases,processes may include additional features not mentioned below, orfurther processes may be added.

At 310, device 305-a may optionally determine a polynomial associatedwith an efficiency of an energy harvesting circuit at device 305-a. Thatis, in cases when using a non-linear energy harvesting model, device305-a may determine a K-coefficient polynomial to represent the behaviorof the energy harvesting circuit (e.g., as described with reference toEquation 3). At 315, device 305-a may transmit an indication of anenergy conversion efficiency factor and a threshold power parameter todevice 305-b. The indication may be associated with the energyharvesting circuit at device 305-a. In some examples, device 305-a maybe configured to use a linear energy harvesting model (e.g., asdescribed with reference to Equation 1). As such, device 305-a maytransmit the indication with the energy conversion efficiency factor. Inother examples, device 305-a may be configured to use a piecewise linearenergy harvesting model (e.g., as described with reference to Equation2). Here, device 305-a may transmit the indication with the energyconversion efficiency factor and the threshold power parameter. In yetother examples, device 305-a may be configured to use a non-linearenergy harvesting model (e.g., as described with reference to Equation3). In these examples, device 305-a may transmit the indicationincluding the threshold power parameter and more than one energyconversion efficiency factors. That is, the indication may indicate aquantity of terms in the polynomial (e.g., K) and the coefficients ofthe polynomial which each corresponding to an energy conversionefficiency factor). In some examples, device 305-a may transmit theindication as (or within) Uu RRC signaling, sidelink RRC signaling, a UuMAC-CE, a sidelink MAC-CE, control information (e.g., uplink controlinformation (UCI), sidelink control information (SCI), downlink controlinformation (DCI)), or a combination thereof. In some examples, device305-a may transmit the second indication as (or within) MAC-CEs,sidelink MAC-CEs, physical uplink channel transmissions (e.g., physicaluplink shared channel (PUSCH), physical sidelink shared channel (PSSCH),or any other uplink channel), or a combination thereof.

At 320, device 305-a may optionally transmit a target power indicationto device 305-b. In other words, device 305-a may transmit, to device305-b, an indication of a target amount of power that the device 305-aconverts (e.g., from radio frequency power to DC power). The targetamount of converted power may be associated with a desired QoS. Thedevice 305-a may include the indication of the target amount ofconverted power, and in some cases, the desired QoS within theindication transmitted at 315 or another indication. Device 305-a maytransmit the target power indication via a Uu MAC-CE, a sidelink MAC-CE,physical uplink channel transmissions (e.g., PUSCH, PSSCH, or any otheruplink channel), or a combination thereof.

At 325, device 305-b may transmit a signal with a radio frequency powerbased on the one or more indications. For example, device 305-b maydetermine a radio frequency power for the signal according to theindicated energy harvesting circuit characteristics (e.g., based onreceiving the indication at 315, 320, or both). That is, device 305-bmay adjust the radio frequency power of subsequent signals to increase apower efficiency associated with the energy harvesting circuit at device305-a and maintain a certain QoS. Additionally, device 305-b may attemptto transmit signals having sufficient radio frequency power to ensurethat a radio frequency power of signals received by a signal decodingcircuit of device 305-a are associated with the desired QoS. In otherwords, device 305-b may adjust the radio frequency power based on thetarget amount of converted power. Thus, device 305-b may select theradio frequency power based on the energy harvesting procedure indicatedby device 305-a (e.g., via the indications at 315 and 320). Device 305-amay receive the signal including the radio frequency power.

At 330, device 305-a may convert at least a first portion of the radiofrequency power of the signal to DC power. The first portion may bebased on an energy harvesting scheme at device 305-a. For example,device 305-a may be configured to use a separated receiver architecturescheme, where device 305-a may use a specific quantity of antennasassociated with the energy harvesting circuit to receive the signal andradio frequency power. As such, the first portion may be based on thenumber of antennas used for the energy harvesting circuit. In otherexamples, device 305-a may be configured to use a time switching scheme,where device 305-a may use a number of antennas for both the energyharvesting circuit and the signal decoding circuit. As such, the firstportion may be based on the time allocated (e.g., via a time switcher)for the energy harvesting circuit to use the antennas. In yet otherexamples, device 305-a may be configured to use a power splittingscheme, where device 305-a may use a number of antennas for both theenergy harvesting circuit and the signal decoding circuit. As such, thefirst portion may be based on the amount of power diverted (e.g., via apower splitter) to the energy harvesting circuit. Energy harvestingschemes are described in more detail with reference to FIG. 6 .

At 335, device 305-a may store the converted power (e.g., DC power). Insome examples, device 305-a may store the converted power in an energystorage module (e.g., a battery) in the energy harvesting circuit. Theenergy storage module may be used to provide power for tasks such astasks (e.g., associated with relatively low energy) that are associatedwith information transfer (e.g., decoding information, encodinginformation, signal conversion, or other low energy tasks).

In some examples, at 340, device 305-a may decode the signal received at325. Device 305-a may decode the signal as part of the energy harvestingscheme if the device 305-a is configured to use a compatible energyharvesting scheme (e.g., separated receiver architecture, powersplitting architecture, or the like). In other words, the signaldecoding circuit at device 305-a may decode the signal based on a secondportion of the radio frequency power of the signal.

FIG. 4 illustrates an example of a process flow 400 that supportssignaling for energy harvesting at a device 405 in accordance with oneor more aspects of the present disclosure. In some examples, processflow 400 may implement aspects of the systems 100 and 200 as describedwith reference to FIGS. 1 and 2 . For example, the process flow 400 mayillustrate an example of a device 405-a transmitting an indication,including characteristics associated with energy harvesting circuitry,to device 405-b. Additionally, process flow 400 may implement aspects ofthe process flow 300. For example, device 405-a and device 405-b may beexamples of device 305-a and device 305-b, respectively, as describedwith reference to FIG. 3 . Alternative examples of the following may beimplemented, where some processes are performed in a different orderthan described or are not performed. In some cases, processes mayinclude additional features not mentioned below, or further processesmay be added.

At 410, device 405-a may determine one or more power levels associatedwith energy harvesting circuitry at device 405-a. For example, device405-a may determine, for each power level input to the energy harvestingcircuit, a respective power level output from the energy harvestingcircuit (e.g., energy collected by device 405-a).

At 415, device 405-a may transmit an indication of one or more powerlevels output from the energy harvesting circuit that correspond to oneor more power levels being input to the energy harvesting circuit, todevice 405-b. The indication may include a table mapping the one or morepower levels output from the energy harvesting circuit to the one ormore power levels being input to the energy harvesting circuit. Thetable may be based on determining the power levels at 410. The table maybe incremented based on a predefined increment at device 405-a, asignaled increment from device 405-b, or the like. In some examples,device 405-a may transmit the indication as (or within) Uu RRCsignaling, sidelink RRC signaling, a Uu MAC-CE, a sidelink MAC-CE,control information (e.g., UCI, DCI, SCI), or a combination thereof.

In some examples, at 420, device 405-a may transmit second indication todevice 405-b, including a target power indication. In other words,device 405-a may transmit an indication of a target amount of convertedpower (e.g., DC power) to device 405-b. The target amount of convertedpower may be associated with a desired QoS. Device 405-a may include theindication of the target amount of converted power, and in some cases,the desired QoS within the indication transmitted at 415, the secondindication, or another indication. In some examples, device 405-a maytransmit the second indication as (or within) Uu MAC-CEs, sidelinkMAC-CEs, physical uplink channel transmissions (e.g., PUSCH, PSSCH, orany other uplink channel), or a combination thereof.

Device 405-b may receive the indication at 415, the second indication at420, or a combination thereof. Based on receiving the one or moreindications, device 405-b may determine a radio frequency power forsubsequent signaling according to the indicated energy harvestingcircuit characteristics. For example, device 405-b may adjust the radiofrequency power of subsequent signals to increase a power efficiencyassociated with the energy harvesting circuit at device 405-a andmaintain a certain QoS. Additionally, device 405-b may attempt totransmit signals having sufficient radio frequency power to ensure thata radio frequency power of signals received by a signal decoding circuitof device 405-a are associated with the desired QoS. That is, device405-b may adjust the radio frequency power based on the target amount ofconverted power.

At 425, device 405-b may transmit a signal with a radio frequency powerbased on the one or more indications. The radio frequency power may beassociated with power efficiency at device 405-a. For example, the radiofrequency power may correspond to the table mapping the power levelsinput to and output from the energy harvesting circuit at device 405-a.That is, device 405-b may choose the radio frequency power to mitigatewasting transmission resources (e.g., avoiding exceeding a powerthreshold as indicated by the power table). Device 405-a may receive thesignal including the radio frequency power.

At 430, device 405-a may convert at least a first portion of the radiofrequency power of the signal to DC power. The first portion may bebased on an energy harvesting scheme at device 405-a. Energy harvestingschemes are described in more detail with reference to FIG. 6 .

At 435, device 405-a may store the converted power (e.g., DC power). Insome examples, device 405-a may store the converted power in an energystorage module in the energy harvesting circuit. Device 405-a may usethe energy storage module to provide power for low energy tasks such astasks associated with information transfer (e.g., decoding information,encoding information, signal conversion, or other low energy tasks).

In some examples, at 440, device 405-a may decode the signal received at425. Device 405-a may decode the signal as part of the energy harvestingscheme if the device 405-a is configured to use a compatible energyharvesting scheme (e.g., separated receiver architecture, powersplitting architecture, or the like). In other words, the signaldecoding circuit at device 305-a may decode the signal based on a secondportion of the radio frequency power of the signal.

FIG. 5 illustrates an example of a process flow 500 that supportssignaling for energy harvesting at a device 505 in accordance with oneor more aspects of the present disclosure. In some examples, processflow 500 may implement aspects of the systems 100 and 200 as describedwith reference to FIGS. 1 and 2 . For example, the process flow 500 mayillustrate an example of a device 505-a transmitting one or moreindications, including characteristics associated with energy harvestingcircuitry, to device 505-b. Additionally, process flow 500 may implementaspects of the process flow 400. For example, Device 505-a and device505-b may be examples of device 405-a and device 405-b, respectively, asdescribed with reference to FIG. 4 . Alternative examples of thefollowing may be implemented, where some processes are performed in adifferent order than described or are not performed. In some cases,processes may include additional features not mentioned below, orfurther processes may be added.

At 510, device 505-a may transmit an indication of a first power levelto device 505-b. In some examples, device 505-a may transmit theindication of the first power level to device 505-b upon connectionestablishment. For example, device 505-a may transmit the indicationupon entering a network, performing a random access process, after (orpart of) a wake up procedure, or any other connection establishmentevent. The indication of the first power level may correspond to abattery of device 505-a. For example, the first power level mayrepresent an amount of energy stored in the battery. The representationsof the first power level are described in more detail with reference toFIG. 2 . Additionally, device 505-a may include an indication of abattery type (e.g., a lithium ion battery, a lithium polymer battery, orany other type of battery), within the indication of the first powerlevel. Alternatively, the indication of the battery type may be includedin a different indication than the indication of the first power level.In some examples, device 505-a may transmit the indication of the firstpower level, the indication of the battery type, or a combinationthereof as (or within) Uu RRC signaling, sidelink RRC signaling, UuMAC-CEs, sidelink MAC-CEs, physical uplink channel transmissions (e.g.,PUSCH, PSSCH, or any other uplink channel), or a combination thereof.

In some examples, at 515, device 505-a may transmit a second indicationto device 405-b, including a target power indication. That is, device505-a may transmit an indication of a target amount of converted power(e.g., DC power) to device 505-b. The target amount of converted powermay be associated with a desired QoS. Device 505-a may include theindication of the target amount of converted power, and in some cases,the desired QoS, within the indication transmitted at 510, theindication of the battery type, or another indication. In some examples,device 505-a may transmit the second indication as (or within) UuMAC-CEs, sidelink MAC-CEs, physical uplink channel transmissions (e.g.,PUSCH, PSSCH, or any other uplink channel), or a combination thereof.

Device 505-b may receive the indication at 510, the second indication at515, the indication of the battery type, or a combination thereof. Basedon receiving the one or more indications, device 505-b may determine aradio frequency power for subsequent signaling according to theindicated energy harvesting circuit characteristics. For example, device505-b may adjust the radio frequency power of subsequent signals toincrease a power efficiency associated with the energy harvestingcircuit at device 505-a and maintain a certain QoS. Additionally, device505-b may attempt to transmit signals having sufficient radio frequencypower to ensure that a radio frequency power of signals received by asignal decoding circuit of device 505-a are associated with the desiredQoS. That is, device 505-b may adjust the radio frequency power based onthe target amount of converted power.

At 520, device 505-b may transmit a signal with a radio frequency powerbased on the one or more indications. For example, the radio frequencypower may correspond to the battery power levels at device 505-a. Thatis, the radio frequency power may be chosen by device 505-b so as toprovide sufficient power to device 505-a and ensure a sufficient QoS forthe communications between the devices 505. Device 505-a may receive thesignal including the radio frequency power.

At 525, device 505-a may convert at least a first portion of the radiofrequency power of the signal to DC power. The first portion may bebased on an energy harvesting scheme at device 505-a. Energy harvestingschemes are described in more detail with reference to FIG. 6 .

At 530, device 505-a may store the converted power (e.g., DC power). Insome examples, device 505-a may store the converted power in an energystorage module in the energy harvesting circuit. Device 505-a may usethe energy storage module to provide power for low energy tasks such astasks associated with information transfer (e.g., decoding information,encoding information, signal conversion, or other low energy tasks).

In some examples, at 535, device 505-b may transmit, to device 505-a, arequest for an indication of a second power level. Device 505-b maytransmit the request based on an event such as receiving an indicationof a random access procedure, a timer configured at device 505-b, or anyother event triggering device 505-b to request the indication of thesecond power level.

At 540, device 505-a may transmit an indication of a second power levelto device 505-b. The second power level may correspond to the amount ofenergy stored in the battery of device 505-a. Device 505-a may transmitthe indication of the second power level based on an event at device505-a such as receiving the request at 535, a timer configured at device505-a, a wake-up procedure, a state of the battery (e.g., a low powerstate), or any other event triggering device 505-a to transmit theindication of the second power level. In some cases, device 505-a mayinclude an updated target amount of converted power in the indication ofthe second power level. The updated target amount of converted power maybe based on the power level of the battery, a change in channelconditions, or the like. In some examples, device 505-a may transmit theindication of the second power level as (or within) Uu RRC signaling,sidelink RRC signaling, Uu MAC-CEs, sidelink MAC-CEs, physical uplinkchannel transmissions (e.g., PUSCH, PSSCH, or any other uplink channel),or a combination thereof.

At 545, device 505-b may transmit a second signal with a second radiofrequency power based on the indication of the second power level.Device 505-b may choose the second radio frequency power to providesufficient power to device 505-a and ensure a sufficient QoS for thecommunications between the devices 505. In some examples, the secondradio frequency power may be based on the indication received at 540, atarget amount of converted power (e.g., the updated target amount ofconverted power), or a combination thereof. Device 505-a may receive thesecond signal including the second radio frequency power.

At 550, device 505-a may convert at least a first portion of the secondradio frequency power of the signal to DC power. The first portion ofthe second radio frequency power may be based on an energy harvestingscheme at device 505-a. Energy harvesting schemes are described in moredetail with reference to FIG. 6 .

At 555, device 505-a may store the converted power (e.g., DC power). Insome examples, device 505-a may store the converted power in an energystorage module in the energy harvesting circuit. Device 505-a may usethe energy storage module to provide power for low energy tasks such astasks associated with information transfer (e.g., decoding information,encoding information, signal conversion, or other low energy tasks).

FIGS. 6A through 6C illustrate examples of energy harvesting schemes 600that support signaling for energy harvesting at a device in accordancewith aspects of the present disclosure. In some examples, energyharvesting schemes 600 may implement aspects of systems 100 and 200 asdescribed with reference to FIGS. 1 through 5 . For example, basestations 105, UEs 115, and devices 205, 305, 405, and 505 may beequipped with sufficient circuitry to implement one or more energyharvesting schemes 600. FIG. 6A illustrates an energy harvesting scheme600-a associated with a separated receiver architecture, FIG. 6Billustrates an energy harvesting scheme 600-b associated with a timeswitching architecture, and FIG. 6C illustrates an energy harvestingscheme 600-c associated with a power splitting architecture.

In some examples, a device may be configured to support energyharvesting. That is, the device may contain (or have access to)circuitry that may perform according to one or more energy harvestingschemes 600 (e.g., energy harvesting circuits 610). In any case, thedevice may be equipped with one or more antennas 605 with which thedevice may use to receive radio frequency power from signals. The radiofrequency power may be directed to an energy harvesting circuit 610, asignal decoding circuit 615, or a combination thereof.

FIG. 6A illustrates an example energy harvesting scheme 600-a used by adevice having a separated receiver architecture. As such, the device maybe equipped with a set of antennas 605-a where a first portion of theset of antennas 605-a may be associated with energy harvesting circuit610-a and a second portion of the set of antennas 605-a may beassociated with signal decoding circuit 615-a. That is, the portion ofthe antennas 605-a associated with the energy harvesting circuit 610-amay direct received radio frequency power to the energy harvestingcircuit 610-a and the portion of the antennas 605-a associated with thesignal decoding circuit 615-a may direct received radio frequency powerto the signal decoding circuit 615-a. For example, the device may usefour of the antennas 605-a for energy harvesting and 96 of the antennas605-a for signal decoding. The number of antennas for energy harvestingand the number of antennas for signal decoding may be fixed (e.g.,predefined during a manufacturing stage), configurable (e.g., based onautonomous determination at the device), or a combination thereof. Usingsuch an architecture, the device may receive a signal with the set ofantennas 605-a and may both decode the signal (e.g., using the signaldecoding circuit 615-a) and harvest energy from the radio frequencypower of the signal (e.g., using the energy harvesting circuit 610-a).That is, in a given time period the device may use the energy harvestingcircuit 610-a to convert a first portion of the radio frequency power toDC power and the device may use the signal decoding circuit 615-a todecode the signal based on a second portion of the radio frequencypower.

FIG. 6B illustrates an energy harvesting scheme 600-b associated with atime switching architecture. In such an example, a device may beequipped with a time switcher 620 that the device may use to selectivelydivert power, received from the antenna 605-b, to one or more componentsin the device. For example, the device may divert power to energyharvesting circuit 610-b for a first time period where, after the firsttime period, the device may divert power to signal decoding circuit615-b for a second time period. That is, the energy harvested by thedevice may depend on the operation of the time switcher 620. As anillustrative example, the device may store an amount of energyrepresented by Equation 4:

E _(j) =ηP _(i) |g _(i-j)|² Tα  (4)

In Equation 4, α may represent a fraction of time allocated for energyharvesting. As such, the time switcher 620 may be configured to directpower to the energy harvesting circuit 610-b for a time weighted by thefactor α and may be configured to direct power to the signal decodingcircuit 615-b for a time weighted by the factor 1−α. For example, thetime switcher 620 may be configured to direct a first portion ofreceived radio frequency power to the energy harvesting circuit 610-bfor αT and to direct a second portion of received radio frequency powerto the signal decoding circuit 615-b for (1−α)T. α may be predefined atthe device, determined at the device (e.g., based on a QoS), signaled byanother device, or the like. Using such an architecture, the device mayreceive a signal with the antennas 605-b and may both decode the signal(e.g., using the signal decoding circuit 615-b) and harvest energy fromthe radio frequency power of the signal (e.g., using the energyharvesting circuit 610-b). That is, at a first time, the device may usethe energy harvesting circuit 610-b to convert a first portion of theradio frequency power to DC power and, at a second time, the device mayuse the signal decoding circuit 615-b to decode the signal based on asecond portion of the radio frequency power.

FIG. 6C illustrates an energy harvesting scheme 600-c associated with apower splitting architecture. As such, the device may be equipped with apower splitter 625 that the device may use to split power, received fromthe antenna 605-c, to one or more components in the device. For example,the device may split received radio frequency power, directing a firstportion of the radio frequency power to energy harvesting circuit 610-cand a second portion of the radio frequency power to signal decodingcircuit 615-c. Thus, the energy harvested by the device may depend onthe operation of the power splitter 625. As an illustrative example, thedevice may store an amount of energy represented by Equation 5:

E _(j) =ηρP _(i) |g _(i-j)|² T  (5)

In Equation 5, ρ may represent a fraction of power allocated for energyharvesting. As such, in a given time period, the power splitter 625 maybe configured to split received radio frequency power, directing a firstportion of the radio frequency power (e.g., weighted by ρ) to the energyharvesting circuit 610-c and directing a second portion of the radiofrequency power (e.g., weighted by 1−ρ) to the signal decoding circuit615-c. Using such an architecture, the device may receive a signal withthe antenna 605-c and may both decode the signal (e.g., using the signaldecoding circuit 615-c) and harvest energy from the radio frequencypower of the signal (e.g., using the energy harvesting circuit 610-c).That is, in a given time period the device may use the energy harvestingcircuit 610-c to convert a first portion of the radio frequency power toDC power and the device may use the signal decoding circuit 615-c todecode the signal based on a second portion of the radio frequencypower.

While described individually, in some examples, a device may employ acombination of energy harvesting schemes 600. That is, the device mayhave circuitry enabling the device to utilize more than one energyharvesting scheme 600. For example, the device may contain a timeswitcher 620 and a power splitter 625 such that the device may use acombination of a time switching energy harvesting scheme 600-b and apower splitting energy harvesting scheme 600-c.

In some examples the device may signal one or more characteristics, toanother device, that may depend on the energy harvesting scheme used bythe device. For example, the device may include a number of antennas 605associated with an energy harvesting circuit 610, a parameter indicatinga time associated with energy harvesting, a parameter indicating afraction of power associated with energy harvesting, or the like, withinone or more indications such as those described with reference to theprocess flows 300, 400, and 500.

FIG. 7 illustrates an example of circuitry 700 that supports signalingfor energy harvesting at a device in accordance with aspects of thepresent disclosure. In some examples, circuitry 700 may implementaspects of systems 100 and 200 as described with reference to FIGS. 1through 6 . For example, devices (e.g., as described with reference toFIGS. 1 through 6 ) may include circuitry 700 to perform energyharvesting.

In some examples, the circuitry 700 may include diodes, capacitors,inductors, and other circuit components combined and configured to allowcircuitry 700 to perform energy harvesting. The circuitry 700 mayinclude an energy harvesting circuit 705 (e.g., which may be an exampleof energy harvesting circuits as described herein). The energyharvesting circuit 705 may include a radio frequency energy harvester715, a power management module 720, and an energy storage 725. The radiofrequency energy harvester 715 may convert radio frequency power to DCpower. For example, the radio frequency energy harvester 715 may receivea radio frequency input 730 from an antenna (e.g., a radio frequencyantenna) and, using one or more components such as an impedance matchingcircuit 735, a voltage multiplier 740, a capacitor 745, the radiofrequency energy harvester 715 may convert the radio frequency input 730to the DC output 750. For example, the radio frequency energy harvester715 may convert energy from an electromagnetic domain to an electricaldomain. For example, the radio frequency energy harvester 715 mayreceive the radio frequency input 730 (e.g., having power associatedwith an electromagnetic field) and may convert the radio frequency input730 to the DC output 750 (e.g., having power associated with a voltageand current). The power management module 720 may determine to store theDC output 750 (e.g., at a battery) or use the DC output 750 for lowpower tasks (e.g., information transmission) subsequent to theconversion. Such low power tasks may include providing power to any oneof the components within the circuitry 700 (e.g., radio frequency energyharvester 715, power management module 720, lower-power radio frequencytransceiver 755, lower-power microcontroller 760, antennas, amongothers). Upon deciding to store the energy output, the power managementmodule 720 may store the energy output in the energy storage 725.

In some examples, the circuitry may include a signal decoding circuit710 to perform tasks associated with information transmission andreception. For example, the signal decoding circuit 710 may include alower-power radio frequency transceiver 755, a lower-powermicrocontroller 760, and an application 765. The lower-power radiofrequency transceiver 755 may transmit and receive signals. Thelower-power microcontroller 760 may process data. For example, thelower-power microcontroller 760 may process data received fromlower-power radio frequency transceiver 755. In another example, thelower-power microcontroller 760 may receive data from the application765, where the lower-power microcontroller 760 may process the data andtransmit the processed data to the lower-power radio frequencytransceiver 755 for subsequent transmission. The lower-powermicrocontroller may 760 process data using power received from the powermanagement module 720. For example, the power management module 720 maydirect energy output from the radio frequency energy harvester 715 tothe lower-power microcontroller 760. In another example, the powermanagement module 720 may receive energy from the energy storage 725 anddirect the energy to the lower-power microcontroller 760. As such, thelower-power microcontroller 760 may receive the energy from the powermanagement module 720 for processing data.

Utilizing the signaling techniques for energy harvesting as describedherein may allow a device to perform energy harvesting efficiently,increasing the amount of energy received from a signal for performinglow energy tasks. Thus, the device may increase battery life andmaintain a desired QoS for communications.

FIG. 8 illustrates an example of a power diagram 800 that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure. In some examples, power diagram800 may illustrate a relationship between the radio frequency input 730and the DC output in circuitry 700 as described with reference to FIG. 7.

Power diagram 800 may relate input radio frequency power (e.g., fromsignaling from a transmitting device) into an energy harvesting circuitto the output DC power converted by the energy harvesting circuit. As anillustrative example, power diagram 800 may be associated with apiecewise linear energy harvesting model. However, a device may beassociated with other power diagrams 800 associated with a linear energyharvesting model, a non-linear energy harvesting model (e.g., apolynomial model), or any other energy harvesting model. For example,the power diagram 800 may be associated with a polynomial energyharvesting model (e.g., as described with reference to Equation 3).Here, the regional curve start point (e.g., P_(Start) (0) may be by 0(or substantially near 0), the saturation portion start point (e.g.,P_(th LOW) (0) may correspond to the threshold power 805, and thesaturation portion end point (e.g., P_(th HIGH)(L)) may be infinity mW.

In the example provided in power diagram 800, up until a threshold power805, an increase in the input radio frequency power may correspond to alinear increase of the output DC power. The slope of this linearrelationship may be represented by an energy conversion efficiencyfactor. Increasing the input radio frequency power past the thresholdpower 805 may result in no change to the output DC power. That is, theenergy harvesting circuit may have a saturation power, such as convertedthreshold power 810. Thus, an input radio frequency power equal (orsubstantially equivalent) to the threshold power 805 may correspond toefficient system function. However, in some cases, a transmitting devicemay be unaware of the power diagram 800 or the characteristics thereof.Thus, the transmitting device may be unaware of potential inefficiencieswhen transmitting signals. For example, the transmitting device maytransmit signals unaware of the energy harvesting circuitcharacteristics and may transmit a signal to a receiving device with aninput radio frequency power that is greater than the threshold power805.

Implementing the techniques as described herein may allow devices tosignal for energy harvesting enabling devices to maximize output DCpower while mitigating the waste of communication resources.

FIG. 9 shows a block diagram 900 of a device 905 that supports signalingfor energy harvesting at a device in accordance with one or more aspectsof the present disclosure. The device 905 may be an example of aspectsof a First Device as described herein. The device 905 may include areceiver 910, a transmitter 915, and a communications manager 920. Thedevice 905 may also include a processor. Each of these components may bein communication with one another (e.g., via one or more buses).

The receiver 910 may provide a means for receiving information such aspackets, user data, control information, or any combination thereofassociated with various information channels (e.g., control channels,data channels, information channels related to signaling for energyharvesting at a device). Information may be passed on to othercomponents of the device 905. The receiver 910 may utilize a singleantenna or a set of multiple antennas.

The transmitter 915 may provide a means for transmitting signalsgenerated by other components of the device 905. For example, thetransmitter 915 may transmit information such as packets, user data,control information, or any combination thereof associated with variousinformation channels (e.g., control channels, data channels, informationchannels related to signaling for energy harvesting at a device). Insome examples, the transmitter 915 may be co-located with a receiver 910in a transceiver module. The transmitter 915 may utilize a singleantenna or a set of multiple antennas.

The communications manager 920, the receiver 910, the transmitter 915,or various combinations thereof or various components thereof may beexamples of means for performing various aspects of signaling for energyharvesting at a device as described herein. For example, thecommunications manager 920, the receiver 910, the transmitter 915, orvarious combinations or components thereof may support a method forperforming one or more of the functions described herein.

In some examples, the communications manager 920, the receiver 910, thetransmitter 915, or various combinations or components thereof may beimplemented in hardware (e.g., in communications management circuitry).The hardware may include a processor, a digital signal processor (DSP),an application specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, a discrete gate ortransistor logic, discrete hardware components, or any combinationthereof configured as or otherwise supporting a means for performing thefunctions described in the present disclosure. In some examples, aprocessor and memory coupled with the processor may be configured toperform one or more of the functions described herein (e.g., byexecuting, by the processor, instructions stored in the memory).

Additionally or alternatively, in some examples, the communicationsmanager 920, the receiver 910, the transmitter 915, or variouscombinations or components thereof may be implemented in code (e.g., ascommunications management software or firmware) executed by a processor.If implemented in code executed by a processor, the functions of thecommunications manager 920, the receiver 910, the transmitter 915, orvarious combinations or components thereof may be performed by ageneral-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or anycombination of these or other programmable logic devices (e.g.,configured as or otherwise supporting a means for performing thefunctions described in the present disclosure).

In some examples, the communications manager 920 may be configured toperform various operations (e.g., receiving, monitoring, transmitting)using or otherwise in cooperation with the receiver 910, the transmitter915, or both. For example, the communications manager 920 may receiveinformation from the receiver 910, send information to the transmitter915, or be integrated in combination with the receiver 910, thetransmitter 915, or both to receive information, transmit information,or perform various other operations as described herein.

The communications manager 920 may support wireless communication at afirst device in accordance with examples as disclosed herein. Forexample, the communications manager 920 may be configured as orotherwise support a means for transmitting, to a second device, anindication of an energy conversion efficiency factor and a thresholdpower parameter. The communications manager 920 may be configured as orotherwise support a means for receiving, from the second device, asignal including a radio frequency power, where the radio frequencypower is based on the transmitted indication. The communications manager920 may be configured as or otherwise support a means for converting atleast a first portion of the radio frequency power of the signal to DCpower.

Additionally or alternatively, the communications manager 920 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. For example, the communications manager920 may be configured as or otherwise support a means for transmitting,to a second device, an indication of a set of power levels including afirst quantity of input radio frequency power levels and a secondquantity of output DC power levels. The communications manager 920 maybe configured as or otherwise support a means for receiving, from thesecond device, a signal having a radio frequency power that is based onthe transmitted indication. The communications manager 920 may beconfigured as or otherwise support a means for converting at least afirst portion of the radio frequency power of the signal to DC power.

Additionally or alternatively, the communications manager 920 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. For example, the communications manager920 may be configured as or otherwise support a means for transmitting,to a second device, a first indication of a first power level of abattery of the first device. The communications manager 920 may beconfigured as or otherwise support a means for receiving, from thesecond device, a signal including a radio frequency power, where theradio frequency power is based on the transmitted first indication. Thecommunications manager 920 may be configured as or otherwise support ameans for storing at least a first portion of the radio frequency powerof the signal as DC power at the first device. The communicationsmanager 920 may be configured as or otherwise support a means fortransmitting, based on the storing, a second indication of a secondpower level of the battery to the second device.

By including or configuring the communications manager 920 in accordancewith examples as described herein, the device 905 (e.g., a processorcontrolling or otherwise coupled to the receiver 910, the transmitter915, the communications manager 920, or a combination thereof) maysupport techniques for signaling as part of energy harvesting,mitigating wasted transmission resources at a transmitting device andmaximizing DC power acquisition.

FIG. 10 shows a block diagram 1000 of a device 1005 that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure. The device 1005 may be anexample of aspects of a device 905 or a first device as describedherein. The device 1005 may include a receiver 1010, a transmitter 1015,and a communications manager 1020. The device 1005 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

The receiver 1010 may provide a means for receiving information such aspackets, user data, control information, or any combination thereofassociated with various information channels (e.g., control channels,data channels, information channels related to signaling for energyharvesting at a device). Information may be passed on to othercomponents of the device 1005. The receiver 1010 may utilize a singleantenna or a set of multiple antennas.

The transmitter 1015 may provide a means for transmitting signalsgenerated by other components of the device 1005. For example, thetransmitter 1015 may transmit information such as packets, user data,control information, or any combination thereof associated with variousinformation channels (e.g., control channels, data channels, informationchannels related to signaling for energy harvesting at a device). Insome examples, the transmitter 1015 may be co-located with a receiver1010 in a transceiver module. The transmitter 1015 may utilize a singleantenna or a set of multiple antennas.

The device 1005, or various components thereof, may be an example ofmeans for performing various aspects of signaling for energy harvestingat a device as described herein. For example, the communications manager1020 may include an indication transmitter 1025, a signal receiver 1030,a radio frequency power converter 1035, a DC power storage component1040, or any combination thereof. The communications manager 1020 may bean example of aspects of a communications manager 920 as describedherein. In some examples, the communications manager 1020, or variouscomponents thereof, may be configured to perform various operations(e.g., receiving, monitoring, transmitting) using or otherwise incooperation with the receiver 1010, the transmitter 1015, or both. Forexample, the communications manager 1020 may receive information fromthe receiver 1010, send information to the transmitter 1015, or beintegrated in combination with the receiver 1010, the transmitter 1015,or both to receive information, transmit information, or perform variousother operations as described herein.

The communications manager 1020 may support wireless communication at afirst device in accordance with examples as disclosed herein. Theindication transmitter 1025 may be configured as or otherwise support ameans for transmitting, to a second device, an indication of an energyconversion efficiency factor and a threshold power parameter. The signalreceiver 1030 may be configured as or otherwise support a means forreceiving, from the second device, a signal including a radio frequencypower, where the radio frequency power is based on the transmittedindication. The radio frequency power converter 1035 may be configuredas or otherwise support a means for converting at least a first portionof the radio frequency power of the signal to DC power.

Additionally or alternatively, the communications manager 1020 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. The indication transmitter 1025 may beconfigured as or otherwise support a means for transmitting, to a seconddevice, an indication of a set of power levels including a firstquantity of input radio frequency power levels and a second quantity ofoutput DC power levels. The signal receiver 1030 may be configured as orotherwise support a means for receiving, from the second device, asignal having a radio frequency power that is based on the transmittedindication. The radio frequency power converter 1035 may be configuredas or otherwise support a means for converting at least a first portionof the radio frequency power of the signal to DC power.

Additionally or alternatively, the communications manager 1020 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. The indication transmitter 1025 may beconfigured as or otherwise support a means for transmitting, to a seconddevice, a first indication of a first power level of a battery of thefirst device. The signal receiver 1030 may be configured as or otherwisesupport a means for receiving, from the second device, a signalincluding a radio frequency power, where the radio frequency power isbased on the transmitted first indication. The DC power storagecomponent 1040 may be configured as or otherwise support a means forstoring at least a first portion of the radio frequency power of thesignal as DC power at the first device. The indication transmitter 1025may be configured as or otherwise support a means for transmitting,based on the storing, a second indication of a second power level of thebattery to the second device.

FIG. 11 shows a block diagram 1100 of a communications manager 1120 thatsupports signaling for energy harvesting at a device in accordance withone or more aspects of the present disclosure. The communicationsmanager 1120 may be an example of aspects of a communications manager920, a communications manager 1020, or both, as described herein. Thecommunications manager 1120, or various components thereof, may be anexample of means for performing various aspects of signaling for energyharvesting at a device as described herein. For example, thecommunications manager 1120 may include an indication transmitter 1125,a signal receiver 1130, a radio frequency power converter 1135, a DCpower storage component 1140, a signal decoding component 1145, a powertable mapping component 1150, a power level comparator 1155, anindication request receiver 1160, an energy harvesting polynomialcomponent 1165, or any combination thereof. Each of these components maycommunicate, directly or indirectly, with one another (e.g., via one ormore buses).

The communications manager 1120 may support wireless communication at afirst device in accordance with examples as disclosed herein. Theindication transmitter 1125 may be configured as or otherwise support ameans for transmitting, to a second device, an indication of an energyconversion efficiency factor and a threshold power parameter. The signalreceiver 1130 may be configured as or otherwise support a means forreceiving, from the second device, a signal including a radio frequencypower, where the radio frequency power is based on the transmittedindication. The radio frequency power converter 1135 may be configuredas or otherwise support a means for converting at least a first portionof the radio frequency power of the signal to DC power.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting, to the second device, asecond indication of one or more additional energy conversion efficiencyfactors.

In some examples, the energy harvesting polynomial component 1165 may beconfigured as or otherwise support a means for determining, by the firstdevice, a model associated with an efficiency of energy harvesting,where the energy conversion efficiency factor and the one or moreadditional energy conversion efficiency factors are based on the model.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting, to the second device, asecond indication of a target amount of converted DC power, where theradio frequency power of the received signal is further based on thetarget amount of converted DC power.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting the second indication viaa MAC-CE, a transmission via a physical uplink channel, or a combinationthereof.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting the indication via RRCsignaling, a MAC-CE, control information, or a combination thereof.

In some examples, the DC power storage component 1140 may be configuredas or otherwise support a means for storing the DC power at the firstdevice based on the converting.

In some examples, the signal decoding component 1145 may be configuredas or otherwise support a means for decoding the signal based on asecond portion of the radio frequency power of the signal.

Additionally or alternatively, the communications manager 1120 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. In some examples, the indicationtransmitter 1125 may be configured as or otherwise support a means fortransmitting, to a second device, an indication of a set of power levelsincluding a first quantity of input radio frequency power levels and asecond quantity of output DC power levels. In some examples, the signalreceiver 1130 may be configured as or otherwise support a means forreceiving, from the second device, a signal having a radio frequencypower that is based on the transmitted indication. In some examples, theradio frequency power converter 1135 may be configured as or otherwisesupport a means for converting at least a first portion of the radiofrequency power of the signal to DC power.

In some examples, the power table mapping component 1150 may beconfigured as or otherwise support a means for transmitting a mappingbetween the first quantity of input radio frequency power levels and thesecond quantity of output DC power levels.

In some examples, the power level comparator 1155 may be configured asor otherwise support a means for determining, for each of the firstquantity of input radio frequency power levels, a corresponding one ofthe second quantity of output DC power levels, where transmitting theindication is based on the determining.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting, to the second device, asecond indication of a target amount of converted DC power, where theradio frequency power of the received signal is based on the targetamount of converted DC power.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting the second indication viaa MAC-CE, a transmission via a physical uplink channel, or a combinationthereof.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting the indication via RRCsignaling, a MAC-CE, control information, or a combination thereof.

In some examples, the DC power storage component 1140 may be configuredas or otherwise support a means for storing the DC power at the firstdevice based on the converting.

In some examples, the signal decoding component 1145 may be configuredas or otherwise support a means for decoding the signal based on asecond portion of the radio frequency power of the signal.

Additionally or alternatively, the communications manager 1120 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. In some examples, the indicationtransmitter 1125 may be configured as or otherwise support a means fortransmitting, to a second device, a first indication of a first powerlevel of a battery of the first device. In some examples, the signalreceiver 1130 may be configured as or otherwise support a means forreceiving, from the second device, a signal including a radio frequencypower, where the radio frequency power is based on the transmitted firstindication. The DC power storage component 1140 may be configured as orotherwise support a means for storing at least a first portion of theradio frequency power of the signal as DC power at the first device. Insome examples, the indication transmitter 1125 may be configured as orotherwise support a means for transmitting, based on the storing, asecond indication of a second power level of the battery to the seconddevice.

In some examples, the indication request receiver 1160 may be configuredas or otherwise support a means for receiving, from the second device, arequest for the second indication of the second power level of thebattery, where transmitting the second indication is based on receivingthe request for the second indication from the second device.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting, to the second device, athird indication of a type of the battery of the first device, wherereceiving the signal is based on transmitting the third indication ofthe type of the battery of the first device.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting, to the second device, athird indication of a target amount of converted DC power, where theradio frequency power of the received signal is based on the targetamount of converted DC power.

In some examples, the indication transmitter 1125 may be configured asor otherwise support a means for transmitting the second indication viaa MAC-CE, a transmission via a physical uplink channel, or a combinationthereof.

In some examples, the signal receiver 1130 may be configured as orotherwise support a means for receiving, from the second device, asecond signal including a second radio frequency power that is based onthe second power level of the battery, where receiving the second signalis based on transmitting the second indication.

In some examples, the radio frequency power converter 1135 may beconfigured as or otherwise support a means for converting at least thefirst portion of the radio frequency power of the signal to the DCpower, where the storing is based on the converting.

FIG. 12 shows a diagram of a system 1200 including a device 1205 thatsupports signaling for energy harvesting at a device in accordance withone or more aspects of the present disclosure. The device 1205 may be anexample of or include the components of a device 905, a device 1005, ora first device (e.g., a UE, a base station, a sidelink enabled device,or any other device) as described herein. The device 1205 may includecomponents for bi-directional voice and data communications includingcomponents for transmitting and receiving communications, such as acommunications manager 1220, an I/O controller 1210, a transceiver 1215,an antenna 1225, a memory 1230, code 1235, a processor 1240, andcircuitry 1245. These components may be in electronic communication orotherwise coupled (e.g., operatively, communicatively, functionally,electronically, electrically) via one or more buses (e.g., a bus 1245).

The I/O controller 1210 may manage input and output signals for thedevice 1205. The I/O controller 1210 may also manage peripheralsunincluded within the device 1205. In some cases, the I/O controller1210 may represent a physical connection or port to an externalperipheral. In some cases, the I/O controller 1210 may utilize anoperating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®,UNIX®, LINUX®, or another known operating system. Additionally oralternatively, the I/O controller 1210 may represent or interact with amodem, a keyboard, a mouse, a touchscreen, or a similar device. In somecases, the I/O controller 1210 may be implemented as part of aprocessor, such as the processor 1240. In some cases, a user mayinteract with the device 1205 via the I/O controller 1210 or viahardware components controlled by the I/O controller 1210.

In some cases, the device 1205 may include a single antenna 1225.However, in some other cases, the device 1205 may have more than oneantenna 1225, which may be capable of concurrently transmitting orreceiving multiple wireless transmissions. The transceiver 1215 maycommunicate bi-directionally, via the one or more antennas 1225, wired,or wireless links as described herein. For example, the transceiver 1215may represent a wireless transceiver and may communicatebi-directionally with another wireless transceiver. The transceiver 1215may also include a modem to modulate the packets, to provide themodulated packets to one or more antennas 1225 for transmission, and todemodulate packets received from the one or more antennas 1225. Thetransceiver 1215, or the transceiver 1215 and one or more antennas 1225,may be an example of a transmitter 915, a transmitter 1015, a receiver910, a receiver 1010, or any combination thereof or component thereof,as described herein.

The memory 1230 may include random-access memory (RAM) and read-onlymemory (ROM). The memory 1230 may store computer-readable,computer-executable code 1235 including instructions that, when executedby the processor 1240, cause the device 1205 to perform variousfunctions described herein. The code 1235 may be stored in anon-transitory computer-readable medium such as system memory or anothertype of memory. In some cases, the code 1235 may not be directlyexecutable by the processor 1240 but may cause a computer (e.g., whencompiled and executed) to perform functions described herein. In somecases, the memory 1230 may contain, among other things, a basicinput/output system (BIOS) which may control basic hardware or softwareoperation such as the interaction with peripheral components or devices.

The processor 1240 may include an intelligent hardware device (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 1240 may be configured to operate a memoryarray using a memory controller. In some other cases, a memorycontroller may be integrated into the processor 1240. The processor 1240may be configured to execute computer-readable instructions stored in amemory (e.g., the memory 1230) to cause the device 1205 to performvarious functions (e.g., functions or tasks supporting signaling forenergy harvesting at a device). For example, the device 1205 or acomponent of the device 1205 may include a processor 1240 and memory1230 coupled to the processor 1240, the processor 1240 and memory 1230configured to perform various functions described herein.

In some examples, device 1205 may have circuitry 1245 which may beassociated with energy harvesting at device 1205. For example, circuitry1245 may be (or may include) an energy harvesting circuit such as energyharvesting circuit 220 as described with reference to FIG. 2 . Inanother example, circuitry 1245 may be (or may include) a signaldecoding circuit such as signal decoding circuit 215 as described withreference to FIG. 2 . Circuitry 1245 may include or may support function(or a means of function) for any and all circuitry as described withreference to FIG. 7 .

The communications manager 1220 may support wireless communication at afirst device in accordance with examples as disclosed herein. Forexample, the communications manager 1220 may be configured as orotherwise support a means for transmitting, to a second device, anindication of an energy conversion efficiency factor and a thresholdpower parameter. The communications manager 1220 may be configured as orotherwise support a means for receiving, from the second device, asignal including a radio frequency power, where the radio frequencypower is based on the transmitted indication. The communications manager1220 may be configured as or otherwise support a means for converting atleast a first portion of the radio frequency power of the signal to DCpower.

Additionally or alternatively, the communications manager 1220 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. For example, the communications manager1220 may be configured as or otherwise support a means for transmitting,to a second device, an indication of a set of power levels including afirst quantity of input radio frequency power levels and a secondquantity of output DC power levels. The communications manager 1220 maybe configured as or otherwise support a means for receiving, from thesecond device, a signal having a radio frequency power that is based onthe transmitted indication. The communications manager 1220 may beconfigured as or otherwise support a means for converting at least afirst portion of the radio frequency power of the signal to DC power.

Additionally or alternatively, the communications manager 1220 maysupport wireless communication at a first device in accordance withexamples as disclosed herein. For example, the communications manager1220 may be configured as or otherwise support a means for transmitting,to a second device, a first indication of a first power level of abattery of the first device. The communications manager 1220 may beconfigured as or otherwise support a means for receiving, from thesecond device, a signal including a radio frequency power, where theradio frequency power is based on the transmitted first indication. Thecommunications manager 1220 may be configured as or otherwise support ameans for storing at least a first portion of the radio frequency powerof the signal as DC power at the first device. The communicationsmanager 1220 may be configured as or otherwise support a means fortransmitting, based on the storing, a second indication of a secondpower level of the battery to the second device.

By including or configuring the communications manager 1220 inaccordance with examples as described herein, the device 1205 maysupport techniques for receiving a sufficient amount of radio frequencypower during energy harvesting, increasing communications efficiency,and enhancing system function.

In some examples, the communications manager 1220 may be configured toperform various operations (e.g., receiving, monitoring, transmitting)using or otherwise in cooperation with the transceiver 1215, the one ormore antennas 1225, or any combination thereof. Although thecommunications manager 1220 is illustrated as a separate component, insome examples, one or more functions described with reference to thecommunications manager 1220 may be supported by or performed by theprocessor 1240, the memory 1230, the code 1235, or any combinationthereof. For example, the code 1235 may include instructions executableby the processor 1240 to cause the device 1205 to perform variousaspects of signaling for energy harvesting at a device as describedherein, or the processor 1240 and the memory 1230 may be otherwiseconfigured to perform or support such operations.

FIG. 13 shows a flowchart illustrating a method 1300 that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure. The operations of the method1300 may be implemented by a first device (e.g., a UE, a base station, asidelink enabled device, or any other device) or its components asdescribed herein. For example, the operations of the method 1300 may beperformed by a first device as described with reference to FIGS. 1through 12 . In some examples, a first device may execute a set ofinstructions to control the functional elements of the first device toperform the described functions. Additionally or alternatively, thefirst device may perform aspects of the described functions usingspecial-purpose hardware.

At 1305, the method may include transmitting, to a second device, anindication of an energy conversion efficiency factor and a thresholdpower parameter. The operations of 1305 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 1305 may be performed by an indication transmitter 1125 asdescribed with reference to FIG. 11 .

At 1310, the method may include receiving, from the second device, asignal including a radio frequency power, where the radio frequencypower is based on the transmitted indication. The operations of 1310 maybe performed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 1310 may be performed by a signalreceiver 1130 as described with reference to FIG. 11 .

At 1315, the method may include converting at least a first portion ofthe radio frequency power of the signal to DC power. The operations of1315 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 1315 may be performed bya radio frequency power converter 1135 as described with reference toFIG. 11 .

FIG. 14 shows a flowchart illustrating a method 1400 that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure. The operations of the method1400 may be implemented by a first device (e.g., a UE, a base station, asidelink enabled device, or any other device) or its components asdescribed herein. For example, the operations of the method 1400 may beperformed by a first device as described with reference to FIGS. 1through 12 . In some examples, a first device may execute a set ofinstructions to control the functional elements of the first device toperform the described functions. Additionally or alternatively, thefirst device may perform aspects of the described functions usingspecial-purpose hardware.

At 1405, the method may include transmitting, to a second device, anindication of an energy conversion efficiency factor and a thresholdpower parameter. The operations of 1405 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 1405 may be performed by an indication transmitter 1125 asdescribed with reference to FIG. 11 .

At 1410, the method may include transmitting, to the second device, asecond indication of one or more additional energy conversion efficiencyfactors. The operations of 1410 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1410 may be performed by an indication transmitter 1125 asdescribed with reference to FIG. 11 .

At 1415, the method may include receiving, from the second device, asignal including a radio frequency power, where the radio frequencypower is based on the transmitted indication. The operations of 1415 maybe performed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 1415 may be performed by a signalreceiver 1130 as described with reference to FIG. 11 .

At 1420, the method may include converting at least a first portion ofthe radio frequency power of the signal to DC power. The operations of1420 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 1420 may be performed bya radio frequency power converter 1135 as described with reference toFIG. 11 .

FIG. 15 shows a flowchart illustrating a method 1500 that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure. The operations of the method1500 may be implemented by a first device or its components as describedherein. For example, the operations of the method 1500 may be performedby a first device as described with reference to FIGS. 1 through 12 . Insome examples, a first device may execute a set of instructions tocontrol the functional elements of the first device to perform thedescribed functions. Additionally or alternatively, the first device mayperform aspects of the described functions using special-purposehardware.

At 1505, the method may include transmitting, to a second device, anindication of an energy conversion efficiency factor and a thresholdpower parameter. The operations of 1505 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 1505 may be performed by an indication transmitter 1125 asdescribed with reference to FIG. 11 .

At 1510, the method may include transmitting, to the second device, asecond indication of a target amount of converted DC power, where theradio frequency power of the received signal is further based on thetarget amount of converted DC power. The operations of 1510 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 1510 may be performed by anindication transmitter 1125 as described with reference to FIG. 11 .

At 1515, the method may include receiving, from the second device, asignal including a radio frequency power, where the radio frequencypower is based on the transmitted indication. The operations of 1515 maybe performed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 1515 may be performed by a signalreceiver 1130 as described with reference to FIG. 11 .

At 1520, the method may include converting at least a first portion ofthe radio frequency power of the signal to DC power. The operations of1520 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 1520 may be performed bya radio frequency power converter 1135 as described with reference toFIG. 11 .

FIG. 16 shows a flowchart illustrating a method 1600 that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure. The operations of the method1600 may be implemented by a first device (e.g., a UE, a base station, asidelink enabled device, or any other device) or its components asdescribed herein. For example, the operations of the method 1600 may beperformed by a first device as described with reference to FIGS. 1through 12 . In some examples, a first device may execute a set ofinstructions to control the functional elements of the first device toperform the described functions. Additionally or alternatively, thefirst device may perform aspects of the described functions usingspecial-purpose hardware.

At 1605, the method may include transmitting, to a second device, anindication of a set of power levels including a first quantity of inputradio frequency power levels and a second quantity of output DC powerlevels. The operations of 1605 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1605 may be performed by an indication transmitter 1125 asdescribed with reference to FIG. 11 .

At 1610, the method may include receiving, from the second device, asignal having a radio frequency power that is based on the transmittedindication. The operations of 1610 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1610 may be performed by a signal receiver 1130 asdescribed with reference to FIG. 11 .

At 1615, the method may include converting at least a first portion ofthe radio frequency power of the signal to DC power. The operations of1615 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 1615 may be performed bya radio frequency power converter 1135 as described with reference toFIG. 11 .

FIG. 17 shows a flowchart illustrating a method 1700 that supportssignaling for energy harvesting at a device in accordance with one ormore aspects of the present disclosure. The operations of the method1700 may be implemented by a first device (e.g., a UE, a base station, asidelink enabled device, or any other device) or its components asdescribed herein. For example, the operations of the method 1700 may beperformed by a first device as described with reference to FIGS. 1through 12 . In some examples, a first device may execute a set ofinstructions to control the functional elements of the first device toperform the described functions. Additionally or alternatively, thefirst device may perform aspects of the described functions usingspecial-purpose hardware.

At 1705, the method may include transmitting, to a second device, afirst indication of a first power level of a battery of the firstdevice. The operations of 1705 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1705 may be performed by an indication transmitter 1125 asdescribed with reference to FIG. 11 .

At 1710, the method may include receiving, from the second device, asignal including a radio frequency power, where the radio frequencypower is based on the transmitted first indication. The operations of1710 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 1710 may be performed bya signal receiver 1130 as described with reference to FIG. 11 .

At 1715, the method may include storing at least a first portion of theradio frequency power of the signal as DC power at the first device. Theoperations of 1715 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 1715may be performed by a DC power storage component 1140 as described withreference to FIG. 11 .

At 1720, the method may include transmitting, based on the storing, asecond indication of a second power level of the battery to the seconddevice. The operations of 1720 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1720 may be performed by an indication transmitter 1125 asdescribed with reference to FIG. 11 .

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communication at a first device,comprising: transmitting, to a second device, an indication of an energyconversion efficiency factor and a threshold power parameter; receiving,from the second device, a signal comprising a radio frequency power,wherein the radio frequency power is based at least in part on thetransmitted indication; and converting at least a first portion of theradio frequency power of the signal to direct current power.

Aspect 2: The method of aspect 1, further comprising: transmitting, tothe second device, a second indication of one or more additional energyconversion efficiency factors.

Aspect 3: The method of aspect 2, further comprising: determining, bythe first device, a model associated with an efficiency of energyharvesting, wherein the energy conversion efficiency factor and the oneor more additional energy conversion efficiency factors are based atleast in part on the model.

Aspect 4: The method of any of aspects 1 through 3, further comprising:transmitting, to the second device, a second indication of a targetamount of converted direct current power, wherein the radio frequencypower of the received signal is further based at least in part on thetarget amount of converted direct current power.

Aspect 5: The method of aspect 4, the transmitting the second indicationcomprising: transmitting the second indication via a media accesscontrol-control element, a transmission via a physical uplink channel,or a combination thereof.

Aspect 6: The method of any of aspects 1 through 5, the transmitting theindication of the energy conversion efficiency factor and the thresholdpower parameter comprising: transmitting the indication via radioresource control signaling, a media access control-control element,control information, or a combination thereof.

Aspect 7: The method of any of aspects 1 through 6, further comprising:storing the direct current power at the first device based at least inpart on the converting.

Aspect 8: The method of any of aspects 1 through 7, further comprising:decoding the signal based at least in part on a second portion of theradio frequency power of the signal.

Aspect 9: A method for wireless communication at a first device,comprising: transmitting, to a second device, an indication of a set ofpower levels comprising a first quantity of input radio frequency powerlevels and a second quantity of output direct current power levels;receiving, from the second device, a signal having a radio frequencypower that is based at least in part on the transmitted indication; andconverting at least a first portion of the radio frequency power of thesignal to direct current power.

Aspect 10: The method of aspect 9, the transmitting the indicationcomprising: transmitting a mapping between the first quantity of inputradio frequency power levels and the second quantity of output directcurrent power levels.

Aspect 11: The method of any of aspects 9 through 10, furthercomprising: determining, for each of the first quantity of input radiofrequency power levels, a corresponding one of the second quantity ofoutput direct current power levels, wherein transmitting the indicationis based at least in part on the determining.

Aspect 12: The method of any of aspects 9 through 11, furthercomprising: transmitting, to the second device, a second indication of atarget amount of converted direct current power, wherein the radiofrequency power of the received signal is based at least in part on thetarget amount of converted direct current power.

Aspect 13: The method of aspect 12, the transmitting the secondindication comprising: transmitting the second indication via a mediaaccess control-control element, a transmission via a physical uplinkchannel, or a combination thereof.

Aspect 14: The method of any of aspects 9 through 13, the transmittingthe indication comprising: transmitting the indication via radioresource control signaling, a media access control-control element,control information, or a combination thereof.

Aspect 15: The method of any of aspects 9 through 14, furthercomprising: storing the direct current power at the first device basedat least in part on the converting.

Aspect 16: The method of any of aspects 9 through 15, furthercomprising: decoding the signal based at least in part on a secondportion of the radio frequency power of the signal.

Aspect 17: A method for wireless communication at a first device,comprising: transmitting, to a second device, a first indication of afirst power level of a battery of the first device; receiving, from thesecond device, a signal comprising a radio frequency power, wherein theradio frequency power is based at least in part on the transmitted firstindication; storing at least a first portion of the radio frequencypower of the signal as direct current power at the first device; andtransmitting, based at least in part on the converting, a secondindication of a second power level of the battery to the second device.

Aspect 18: The method of aspect 17, further comprising: receiving, fromthe second device, a request for the second indication of the secondpower level of the battery, wherein transmitting the second indicationis based at least in part on receiving the request for the secondindication from the second device.

Aspect 19: The method of any of aspects 17 through 18, furthercomprising: transmitting, to the second device, a third indication of atype of the battery of the first device, wherein receiving the signal isbased at least in part on transmitting the third indication of the typeof the battery of the first device.

Aspect 20: The method of any of aspects 17 through 19, furthercomprising: transmitting, to the second device, a third indication of atarget amount of converted direct current power, wherein the radiofrequency power of the received signal is based at least in part on thetarget amount of converted direct current power.

Aspect 21: The method of aspect 20, the transmitting the secondindication comprising: transmitting the second indication via a mediaaccess control-control element, a transmission via a physical uplinkchannel, or a combination thereof.

Aspect 22: The method of any of aspects 17 through 21, furthercomprising: receiving, from the second device, a second signalcomprising a second radio frequency power that is based at least in parton the second power level of the battery, wherein receiving the secondsignal is based at least in part on transmitting the second indication.

Aspect 23: The method of any of aspects 17 through 22, furthercomprising: converting at least the first portion of the radio frequencypower of the signal to the direct current power, wherein the storing isbased at least in part on the converting.

Aspect 24: An apparatus for wireless communication at a first device,comprising a processor; memory coupled to the processor; the processorand memory configured to perform a method of any of aspects 1 through 8.

Aspect 25: An apparatus for wireless communication at a first device,comprising at least one means for performing a method of any of aspects1 through 8.

Aspect 26: A non-transitory computer-readable medium storing code forwireless communication at a first device, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 1 through 8.

Aspect 27: An apparatus for wireless communication at a first device,comprising a processor; memory coupled to the processor; the processorand memory configured to perform a method of any of aspects 9 through16.

Aspect 28: An apparatus for wireless communication at a first device,comprising at least one means for performing a method of any of aspects9 through 16.

Aspect 29: A non-transitory computer-readable medium storing code forwireless communication at a first device, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 9 through 16.

Aspect 30: An apparatus for wireless communication at a first device,comprising a processor; memory coupled to the processor; the processorand memory configured to perform a method of any of aspects 17 through23.

Aspect 31: An apparatus for wireless communication at a first device,comprising at least one means for performing a method of any of aspects17 through 23.

Aspect 32: A non-transitory computer-readable medium storing code forwireless communication at a first device, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 17 through 23.

It should be noted that the methods described herein describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may bedescribed for purposes of example, and LTE, LTE-A, LTE-A Pro, or NRterminology may be used in much of the description, the techniquesdescribed herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NRnetworks. For example, the described techniques may be applicable tovarious other wireless communications systems such as Ultra MobileBroadband (UMB), Institute of Electrical and Electronics Engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, aswell as other systems and radio technologies not explicitly mentionedherein.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, a CPU, an FPGA or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyprocessor, controller, microcontroller, or state machine. A processormay also be implemented as a combination of computing devices (e.g., acombination of a DSP and a microprocessor, multiple microprocessors, oneor more microprocessors in conjunction with a DSP core, or any othersuch configuration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described herein may be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that may beaccessed by a general-purpose or special-purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media mayinclude RAM, ROM, electrically erasable programmable ROM (EEPROM), flashmemory, compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that may be used to carry or store desired programcode means in the form of instructions or data structures and that maybe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of computer-readable medium. Disk and disc,as used herein, include CD, laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an example step that is described as “based on condition A”may be based on both a condition A and a condition B without departingfrom the scope of the present disclosure. In other words, as usedherein, the phrase “based on” shall be construed in the same manner asthe phrase “based at least in part on.”

The term “determine” or “determining” encompasses a wide variety ofactions and, therefore, “determining” can include calculating,computing, processing, deriving, investigating, looking up (such as vialooking up in a table, a database or another data structure),ascertaining and the like. Also, “determining” can include receiving(such as receiving information), accessing (such as accessing data in amemory) and the like. Also, “determining” can include resolving,selecting, choosing, establishing and other such similar actions.

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “example” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, known structures and devices are shown inblock diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person having ordinaryskill in the art to make or use the disclosure. Various modifications tothe disclosure will be apparent to a person having ordinary skill in theart, and the generic principles defined herein may be applied to othervariations without departing from the scope of the disclosure. Thus, thedisclosure is not limited to the examples and designs described hereinbut is to be accorded the broadest scope consistent with the principlesand novel features disclosed herein.

What is claimed is:
 1. An apparatus for wireless communication,comprising: a processor; and memory coupled to the processor, theprocessor and memory configured to: transmit, to a device, an indicationof an energy conversion efficiency factor and a threshold powerparameter; receive, from the device, a signal comprising a radiofrequency power that is based at least in part on the transmittedindication; and convert at least a first portion of the radio frequencypower of the signal to direct current power.
 2. The apparatus of claim1, further comprising: an energy harvesting circuit, coupled with theprocessor and memory, configured to convert radio frequency power todirect current power according to the energy conversion efficiencyfactor and the threshold power parameter.
 3. The apparatus of claim 1,wherein the processor and memory are further configured to: transmit, tothe device, a second indication of one or more additional energyconversion efficiency factors.
 4. The apparatus of claim 3, wherein theprocessor and memory are further configured to: determine a modelassociated with an efficiency of energy harvesting, wherein the energyconversion efficiency factor and the one or more additional energyconversion efficiency factors are based at least in part on the model.5. The apparatus of claim 1, wherein the processor and memory arefurther configured to: transmit, to the device, a second indication of atarget amount of converted direct current power, wherein the radiofrequency power of the received signal is based at least in part on thetarget amount of converted direct current power.
 6. The apparatus ofclaim 1, the transmitting the indication of the energy conversionefficiency factor and the threshold power parameter comprising:transmitting radio resource control signaling, a media accesscontrol-control element, control information, or a combination thereof.7. The apparatus of claim 1, further comprising: a signal decodingcircuit, coupled with the processor and memory, configured to decode thesignal based at least in part on a second portion of the radio frequencypower of the signal.
 8. A method for wireless communication at a firstdevice, comprising: transmitting, to a second device, an indication ofan energy conversion efficiency factor and a threshold power parameter;receiving, from the second device, a signal comprising a radio frequencypower, wherein the radio frequency power is based at least in part onthe transmitted indication; and converting at least a first portion ofthe radio frequency power of the signal to direct current power.
 9. Themethod of claim 8, further comprising: transmitting, to the seconddevice, a second indication of one or more additional energy conversionefficiency factors.
 10. The method of claim 9, further comprising:determining, by the first device, a model associated with an efficiencyof energy harvesting, wherein the energy conversion efficiency factorand the one or more additional energy conversion efficiency factors arebased at least in part on the model.
 11. The method of claim 8, furthercomprising: transmitting, to the second device, a second indication of atarget amount of converted direct current power, wherein the radiofrequency power of the received signal is further based at least in parton the target amount of converted direct current power.
 12. The methodof claim 11, the transmitting the second indication of the target amountof converted direct current power comprising: transmitting the secondindication via a media access control-control element, a transmissionvia a physical uplink channel, or a combination thereof.
 13. The methodof claim 8, the transmitting the indication of the energy conversionefficiency factor and the threshold power parameter comprising:transmitting the indication via radio resource control signaling, amedia access control-control element, control information, or acombination thereof.
 14. The method of claim 8, further comprising:storing the direct current power at the first device based at least inpart on the converting.
 15. The method of claim 8, further comprising:decoding the signal based at least in part on a second portion of theradio frequency power of the signal.
 16. A method for wirelesscommunication at a first device, comprising: transmitting, to a seconddevice, an indication of a set of power levels comprising a firstquantity of input radio frequency power levels and a second quantity ofoutput direct current power levels; receiving, from the second device, asignal having a radio frequency power that is based at least in part onthe transmitted indication; and converting at least a first portion ofthe radio frequency power of the signal to direct current power.
 17. Themethod of claim 16, the transmitting the indication comprising:transmitting a mapping between the first quantity of input radiofrequency power levels and the second quantity of output direct currentpower levels.
 18. The method of claim 16, further comprising:determining, for each of the first quantity of input radio frequencypower levels, a corresponding one of the second quantity of outputdirect current power levels, wherein transmitting the indication isbased at least in part on the determining.
 19. The method of claim 16,further comprising: transmitting, to the second device, a secondindication of a target amount of converted direct current power, whereinthe radio frequency power of the received signal is based at least inpart on the target amount of converted direct current power.
 20. Themethod of claim 19, the transmitting the second indication comprising:transmitting the second indication via a media access control-controlelement, a transmission via a physical uplink channel, or a combinationthereof.
 21. The method of claim 16, the transmitting the indicationcomprising: transmitting the indication via radio resource controlsignaling, a media access control-control element, control information,or a combination thereof.
 22. The method of claim 16, furthercomprising: storing the direct current power at the first device basedat least in part on the converting.
 23. The method of claim 16, furthercomprising: decoding the signal based at least in part on a secondportion of the radio frequency power of the signal.
 24. A method forwireless communication at a first device, comprising: transmitting, to asecond device, a first indication of a first power level of a battery ofthe first device; receiving, from the second device, a signal comprisinga radio frequency power, wherein the radio frequency power is based atleast in part on the transmitted first indication; storing at least afirst portion of the radio frequency power of the signal as directcurrent power at the first device; and transmitting, based at least inpart on the storing, a second indication of a second power level of thebattery to the second device.
 25. The method of claim 24, furthercomprising: receiving, from the second device, a request for the secondindication of the second power level of the battery, whereintransmitting the second indication is based at least in part onreceiving the request for the second indication from the second device.26. The method of claim 24, further comprising: transmitting, to thesecond device, a third indication of a type of the battery of the firstdevice, wherein receiving the signal is based at least in part ontransmitting the third indication of the type of the battery of thefirst device.
 27. The method of claim 24, further comprising:transmitting, to the second device, a third indication of a targetamount of converted direct current power, wherein the radio frequencypower of the received signal is based at least in part on the targetamount of converted direct current power.
 28. The method of claim 27,the transmitting the second indication comprising: transmitting thesecond indication via a media access control-control element, atransmission via a physical uplink channel, or a combination thereof.29. The method of claim 24, further comprising: receiving, from thesecond device, a second signal comprising a second radio frequency powerthat is based at least in part on the second power level of the battery,wherein receiving the second signal is based at least in part ontransmitting the second indication.
 30. The method of claim 24, furthercomprising: converting at least the first portion of the radio frequencypower of the signal to the direct current power, wherein the storing isbased at least in part on the converting.